Tanning Equipment Encyclopedia

This is a working glossary of the parts, electrical terms and measurement terms that come up when a tanning bed or red light bed is bought, installed, serviced or sold. It covers 99 entries, from acrylic to wiring harness. Stan Pope wrote it from the bench: he has repaired this equipment across Metro Detroit since 1990, and each entry says what the part is, what it does, how it fails and what that failure looks like from the outside. Use the letter index to jump, follow the links inside an entry to the matching parts page or guide, and when the bed in front of you does not match the description, call (248) 545-5577 with the make and model.

A

Acrylic

The clear sheet you lie on or under in a tanning bed. It is a UV-transmitting grade of acrylic, not ordinary window plastic, and it sits between the lamps and the user. Acrylic yellows, hazes and loses UV transmission long before it cracks, so it is replaced on a schedule and not only when it breaks. Hairline cracks spread fast under heat and body weight. See the acrylics page and the replacement guide.

Acrylic, bench

The lower acrylic sheet, the one that carries the user's weight. Bench acrylics are usually thicker than canopy acrylics and are the first to crack, because they flex every session and take the full load at the hips and shoulders. A cracked bench acrylic is a stop-use item. Cleaners not made for acrylic will fog the surface and cut UV transmission. Covered on the acrylics page.

Acrylic, canopy

The upper acrylic sheet in the lid of a lay-down bed. It carries no weight but runs hotter than the bench, so it tends to warp, yellow and pull out of its channel over time. Canopy acrylics are often a different size and thickness than the bench sheet on the same bed, which is why the model number matters when ordering. Clips, channels and edge trim hold it in place and wear out as well.

Action spectrum

A measurement curve that weights each UV wavelength by how strongly it produces a defined effect. In tanning equipment the term almost always refers to the erythema action spectrum, a published reference curve used to turn a raw irradiance reading into an erythemally weighted value. It is a measurement convention, not a property of any one lamp, and it is what lets two lamps with different spectra be compared on the same scale.

Air filter

A foam or fiber pad over the air intakes of the base and canopy. It keeps lint, hair and dust off the fans, ballasts and lamp ends. A clogged filter cuts airflow, raises ballast and lamp temperature, shortens lamp life and eventually trips the thermal cutoff. Filters are washable or disposable and are the cheapest item on the maintenance schedule.

Amperage

The current a bed draws while running, printed on the data plate in amps. It sets the breaker size, the wire gauge and the receptacle type. A bed drawing close to the breaker rating will run but trip under heat or line voltage sag. Lamp count and wattage drive the number: a 24 lamp bed at 100 watts and a 32 lamp bed at 160 watts are very different loads. See electrical requirements.

B

Ballast

The component that limits current to a fluorescent tanning lamp and supplies the voltage to start it. A lamp connected straight to the line would draw runaway current and destroy itself in seconds. Every lamp or pair of lamps has a ballast, mounted on trays inside the base and canopy. Ballasts fail by humming, running hot, dimming their lamps or going dark. Full detail on the ballasts page and in lamp, ballast or starter.

Ballast, electronic

A solid-state ballast that runs the lamp at high frequency instead of line frequency. It is lighter, cooler and quieter than a magnetic ballast, does not need a starter, and holds lamp output steadier as line voltage moves. The trade-off is that it fails all at once rather than gradually, and it is more sensitive to heat and voltage spikes. Electronic and magnetic ballasts are not interchangeable without checking the lamp rating.

Ballast, magnetic

The traditional ballast: a copper coil wound on an iron core, often paired with a capacitor. Magnetic ballasts are heavy, run warm and hum slightly even when healthy. They need a starter to preheat the lamp. They tend to die slowly, with a louder hum, a hot smell, dimming at one end of the bed or lamps that take longer to strike. Many beds built before the mid-2000s run on them, and replacements are still standard parts.

Bench

The lower half of a lay-down bed: the base cabinet, its lamps, ballasts, fans and the bench acrylic. The bench holds the data plate on most models and usually houses the main power connection and contactor. Because it carries weight, its acrylic and the acrylic supports wear faster than anything in the canopy.

Bi-pin

A lamp end with two exposed metal pins that push into a spring-loaded lamp holder. It is the most common base on 100 watt tanning lamps and on most F71 lamps. Bi-pin lamps are rotated a quarter turn to seat them, and a lamp that lights only when wiggled usually has a worn holder, not a bad lamp. The other common base is RDC; the two are not interchangeable.

Booth, stand-up

A vertical tanning unit the user stands in, with lamps arranged in a ring or a horseshoe around the body. Booths carry no acrylic to lie on, so they skip bench cracks and most gas spring work, but they run more lamps at higher wattage and often draw more current than a lay-down bed. Their data plate is usually inside the door frame or low on the back panel.

Breaker

The circuit breaker in the building panel that feeds the bed. It opens the circuit when current runs too high for too long or spikes on a short. A breaker that trips at startup, after twenty minutes, or only on hot days is pointing at three different faults. The bed should be on its own dedicated circuit. Diagnosis in tanning bed keeps tripping breaker.

Breaker, thermal and magnetic trip

Standard breakers trip two ways. The thermal element is a bimetal strip that bends as it heats under a sustained overload and trips after seconds or minutes. The magnetic element is a coil that trips instantly on the heavy current of a short circuit. A tanning bed that trips the instant it starts is usually seeing a short or heavy inrush. One that trips late in a session is overloading the thermal element, often from a weak ballast or a hot panel.

Bronzing lamp

A marketing name for a tanning lamp whose spectrum is weighted toward UVA with a lower share of UVB than a standard lamp. It is the same fluorescent technology; the difference is in the phosphor blend. Lamp makers print a UVB percentage on the lamp or spec sheet, and that number, along with length, wattage and base, is what matters when matching a replacement.

Buck-boost transformer

A small transformer wired in line with the bed's supply to raise or lower incoming voltage by a fixed amount. It is common in commercial buildings that supply 208 volts, where a bed rated for 240 would run dim, slow to strike and hard on its ballasts. A buck-boost brings the line back into the bed's rating. It is sized by the bed's amperage and installed by an electrician.

C

Canopy

The upper half of a lay-down bed: the lid that holds the top lamps, their ballasts, any facial lamps, the canopy acrylic and the fans that cool them. It swings on hinges and is held open by gas springs. The canopy runs hotter than the bench because heat rises into it, so its fans and thermal protection matter more.

Capacitor

A component that stores and releases electrical charge. In tanning beds capacitors appear in magnetic ballast circuits, where they correct power factor and help the lamp strike, and inside fan motors, where they give the motor its starting kick. A failing capacitor shows up as a loud hum, lamps that start slowly or run dim, or a fan that twitches but will not spin. Capacitors can bulge or leak when they fail.

Contactor

A heavy-duty electrically operated switch that connects the full lamp load to power when the timer calls for it. The timer handles a small control signal; the contactor handles the amps. Contactors fail with pitted or welded contacts, a loud chatter or buzz, or a coil that no longer pulls in. A bed that is dead even though the timer counts down, or one that stays on after the timer ends, is often a contactor. See electrical parts and tanning bed will not turn on.

Control board

The circuit board that runs a bed's built-in logic: timer display, cool-down, fan speeds, facial lamp switch, hour counter and in some models fault codes. Boards are model-specific, so they are the hardest part to source on a discontinued bed. Many "bad board" calls are actually a blown fuse, a loose ribbon connector or a failed transformer feeding the board. Covered on the timers and controllers page.

Cool-down timer

A delay built into most timers that keeps the fans running for a few minutes after the lamps shut off. It pulls residual heat out of the ballasts and acrylic, which extends the life of both. A bed that goes completely silent the instant the session ends may have lost its cool-down function, and a bed that will not restart right away is usually just waiting out this period.

Cooling fan

An axial fan that pulls room air through the base and canopy to keep lamps, ballasts and acrylic at working temperature. Most beds have several, plus a separate body fan aimed at the user. Fans fail with noisy bearings, a slow spin or a stalled motor, and a fan failure is the usual first cause of an overheat shutdown. Full coverage on the fans and cooling page.

Cord and plug

The supply cord from the bed to the wall receptacle. On 220 volt beds it ends in a NEMA plug matched to the bed's amperage, often a 6-20, 6-30 or a twist-lock. Cords fail at the strain relief where they enter the bed and at the plug blades, which discolor and loosen under heat. A warm plug or a scorched receptacle face is a fault, not a normal condition.

D

Data plate

The metal or foil label carrying the manufacturer, model, serial number, voltage, amperage and lamp specification. It is the first thing a technician asks for. On lay-down beds it is on the end of the base, inside the base near the lamp ends, or on the rear edge of the canopy. On booths it is inside the door frame or on the back panel. Photograph it before calling about parts.

Dedicated circuit

A circuit from the panel that feeds one tanning bed and nothing else. Beds draw a steady, heavy load for the full session, so sharing a circuit with another bed, a water heater or a dryer invites nuisance trips and brownouts that dim lamps. Breaker size, wire gauge and receptacle all follow from the bed's amperage. The electrician spec sheet lays out what to ask for.

Diagnostic sequence

The order a technician checks a bed that is not working: power at the receptacle, breaker, timer signal, contactor, then ballasts, starters and lamps. Working in this order avoids replacing a lamp when the fault is a dead relay two feet away. The Bed Doctor tool walks through the same sequence from the symptoms you can see, and a video session does it live.

Discharge lamp

Any lamp that makes light by passing current through a gas rather than heating a filament. Every tanning lamp is a discharge lamp: fluorescent tubes are low-pressure mercury discharge lamps, and facial and high-pressure units are high-pressure metal halide discharge lamps. Discharge lamps all need a ballast and all lose output gradually with hours of use.

E

Electrical service

The building's incoming power and panel capacity. A home with a 100 amp service and electric heat may not have room for a 30 amp bed circuit without a panel upgrade. Commercial spaces supplying 208 volts may need a buck-boost transformer. Checking service before a bed arrives is part of every install quote; see installation cost.

Electrode

The tungsten filament at each end of a fluorescent tanning lamp, coated with an emissive material that releases electrons into the gas. The starter or ballast heats it before the lamp strikes. Each start wears a little coating away, which is why short sessions with many starts age lamps faster than hours alone suggest. Dark bands at the lamp ends mean the electrodes are nearly spent.

Equivalent lamp

A replacement lamp from a different maker matched to the original by length, diameter, wattage, base type and UVB percentage. Most beds were never tied to one brand of lamp, and most original lamps have long been discontinued, so equivalents are how older beds stay in service. The lamp code and the bed's label are the two things that need to agree. Details on the lamps page.

Erythema

In equipment terms, the reference endpoint used to weight UV measurement. The erythema action spectrum is a published curve, and an erythemally weighted irradiance is a raw UV reading passed through that curve. The word appears on lamp spec sheets and meter displays, and it is defined here only as a measurement convention. For anything about skin, ask a physician, not a technician.

Exposure schedule

The label fixed to every tanning bed listing the maximum session time and the recommended times for its lamp set. The session timer is set so it cannot exceed the label's maximum. When lamps are changed to a different output, the schedule and the timer limit have to be reviewed together, because the label was written for the original lamp specification.

F

F-number (F71, F73)

The length designation in a fluorescent lamp code, in nominal inches. F71 and F73 are the two common tanning lengths; the glass itself runs a little shorter than the number. In practice F71 lamps are usually bi-pin and F73 lamps are usually RDC, but the bed's label settles it, not the rule of thumb. F59 and other lengths appear in facial positions and compact home beds.

Facial lamp

A separate lamp or lamp group in the canopy positioned at the user's face, usually on its own switch and often on a different technology than the body lamps. Many are high-pressure units behind filter glass; others are short fluorescent tubes. Facial lamps have their own ballast and their own replacement interval, and a cracked filter glass takes the facial out of service until it is replaced.

Filter glass

A plate of special glass mounted in front of a high-pressure lamp. The bare lamp emits across the UV range; the filter passes mainly UVA and blocks the shorter wavelengths. It is part of the lamp system, not an accessory, and the lamp is never run without it. Filter glass cracks from thermal shock and clouds with age, and both conditions call for replacement.

Fuse

A one-time overcurrent protector, usually a glass or ceramic cartridge on the control board, in the ballast compartment or in the timer. A fuse blows because something downstream drew too much current: a shorted ballast, a failed lamp holder, a stuck fan. Replacing the fuse without finding that cause means replacing it again. Diagnosis in fuse keeps blowing.

G

Gas spring

The nitrogen-charged strut that holds the canopy open and lets it close with control. Also called a shock. Gas springs are rated by force in newtons and by length, and a bed uses two or more matched to the canopy weight. They lose charge slowly, so the lid gets heavier over years and then one day will not stay up. Replace them as a set. See gas springs and lid will not stay up.

GFCI

A ground-fault circuit interrupter, a breaker or receptacle that opens when it senses current leaking to ground. Local code may require it in some locations. Beds with magnetic ballasts have enough normal leakage to nuisance trip some GFCI devices, so the bed manufacturer's electrical spec and the local inspector both have a say in whether and how one is used. A GFCI that trips only when the bed starts is a diagnostic clue, not always a bed fault.

Ground

The safety conductor that ties the bed's metal frame back to the panel. Every bed has a ground connection at the cord and bonding points inside the cabinet. A loose or corroded ground will not stop the bed from running but removes its main protection against a frame fault, and it can cause the flickering and interference that get blamed on lamps. Grounding is checked at every install.

H

High-pressure lamp

A compact metal halide lamp with a quartz envelope, run at high internal pressure and high wattage behind filter glass. High-pressure lamps appear as facial units in canopy beds and as the main lamps in dedicated high-pressure beds. They need their own heavy ballast and igniter, run very hot, and are rated for far fewer hours than fluorescent tubes. Handle them by the base with clean gloves; skin oil on quartz shortens life.

HO and VHO

High Output and Very High Output, ratings for fluorescent lamps run at higher current than standard tubes. In tanning, 100 watt lamps are commonly HO and 160 watt lamps are VHO. The rating is set by the ballast, so a VHO lamp in an HO socket runs dim and an HO lamp on a VHO ballast overheats and fails early. Match the lamp to the ballast, not just to the socket length.

Hour meter

A counter, mechanical or digital, that logs the hours lamps have been on since it was last reset. It is the basis for every relamp decision and the best single number when buying a used bed. Meters are reset at relamp, so a low reading on an old bed means recent lamps, not a lightly used machine. Many control boards keep a second, non-resettable total.

Hybrid bed

A bed that combines UV tanning lamps with a second light source, usually red LED arrays or red fluorescent tubes, in the same cabinet. Each system has its own power supply or ballast and often its own timer channel, so a hybrid is two pieces of equipment sharing one acrylic and one set of fans. Service on one side does not fix the other. See red light installation.

I

In-bed timer

A timer mounted on the bed itself, set by the user or attendant at the bed, as opposed to a remote timer at a front desk. Home beds nearly always use one. In-bed timers are tied to the control board and fail with dead displays, buttons that stop responding or counts that run but never fire the contactor. Troubleshooting in timer not working.

Inrush current

The brief surge of current a bed draws in the first fraction of a second when lamps and ballasts energize, well above the running amperage on the data plate. Magnetic ballasts and fan motors are the main contributors. A breaker or fuse that is marginal for the running load will hold during the session and trip on inrush, which is why a bed that fails only at startup is an electrical sizing question first.

Installation

Placing, assembling, wiring and testing a bed at full output in its final location. It includes the electrical circuit, floor clearance for the canopy swing, ventilation and a test session with a UV meter. Cost depends on the circuit run and the bed type; see tanning bed installation cost and red light bed installation cost. Moving a bed is covered in moving a tanning bed.

Interlock

A switch that cuts lamp power when a panel, door or access cover is opened. Not every bed has one, but booths and newer beds often do. A failed or misaligned interlock makes a bed that is fully powered yet will not light, with no other symptom. It is checked early in the diagnostic sequence for exactly that reason.

Irradiance

The power of UV reaching a surface per unit area, usually in milliwatts per square centimeter or watts per square meter. It is what a UV meter reads. Irradiance drops as lamps age, as acrylic yellows and as the meter moves farther from the lamp, so readings are compared at a fixed position against the bed's own baseline from the day it was relamped.

J

Junction box

The enclosed box where the building circuit terminates and the bed's supply connects, either through a receptacle or by a hardwired connection. It belongs to the building side of the install and is where an electrician's work ends and the technician's begins. Loose connections in the junction box produce heat and voltage drop that show up in the bed as dim lamps and slow starts.

L

Lamp code

The string printed near one end of a tanning lamp: length (F71, F73), diameter (T12), wattage (100, 160), base type (bi-pin or RDC), often followed by the maker's spectrum name and a UVB percentage. The bed's own requirement is on the data plate or a canopy label. Those two codes have to agree. The lamps page explains how to read one.

Lamp holder

The socket at each end of a lamp, sometimes called a tombstone. Bi-pin holders grip two pins with spring contacts; RDC holders press against a recessed contact and one end is spring-loaded to let the lamp seat. Holders crack from heat, lose spring tension and arc at the contacts, leaving burn marks. A lamp that flickers at one end or lights only when nudged is a holder problem more often than a lamp problem. Sourced through electrical parts.

Lamp life

The rated hours a lamp will run while holding a stated share of its initial UV output, typically about 1,000 hours for 100 watt lamps and about 800 hours for 160 watt lamps. A lamp lights long past that point, but by then it is producing mostly visible light. Useful output starts falling well before the rating, which is why salons relamp on hours, not burnout. See how often to replace lamps.

LED

A light-emitting diode, the solid-state source used in red light beds and the red side of hybrid beds. LEDs run on a low-voltage driver rather than a ballast, produce a narrow band of wavelengths set at manufacture, and are rated for tens of thousands of hours. They do not fail by burnout so much as by driver failure, overheating or a dead section of an array.

LED driver

The power supply that converts line voltage to the regulated low-voltage DC an LED array needs. It is the ballast's counterpart in a red light bed. Drivers fail from heat and from dirty incoming power, and a dark panel or a strip of dead diodes usually traces to a driver or its connector before the LEDs themselves. Drivers are matched to the array by voltage and current and are not interchangeable by size alone.

Level (bed levels 1 to 5)

Marketing tiers salons use to price their beds, with Level 1 as the basic bed and Level 4 or 5 as the highest-output or high-pressure unit. There is no industry standard behind the numbers; one salon's Level 3 is another's Level 2. In equipment terms the tier roughly tracks lamp count, lamp wattage, facial lamps and session length, which is what the relamp scheduler uses instead of the label.

Low-pressure lamp

The standard fluorescent tanning tube. A small amount of mercury vapor at low pressure conducts current between the electrodes and emits mostly short-wave UV, which the phosphor coating on the inside of the glass converts into the UVA and UVB mix the lamp is rated for. Nearly every lay-down bed and booth runs on low-pressure lamps. See the lamps page.

M

MED

Minimal erythema dose, a reference quantity in UV measurement defined as the erythemally weighted dose used as a unit on meter readouts and in lamp testing. It appears in equipment documents as a scale, the way a kilowatt-hour appears on a utility bill. It is listed here only as a measurement term; its application to any person is a question for a physician.

Mercury vapor

The gas that carries the electric discharge inside every fluorescent and high-pressure tanning lamp. The quantity is small but it is why spent lamps are handled as regulated waste in most places, and why a broken lamp is cleaned up with gloves and ventilation rather than a vacuum. Lamp recyclers and many electrical suppliers take spent tubes; a relamp of a 40 lamp bed produces 40 of them.

Model number

The manufacturer's designation for the bed, printed on the data plate. The same model name can hide several production runs with different acrylic sizes, ballast types and timers, so the serial number and a photo of the plate matter as much as the name. A technician works from model, serial and lamp label together when confirming a part. See parts by request.

N

Nanometer

The unit UV wavelengths are measured in, one billionth of a meter, abbreviated nm. Tanning spec sheets use it to describe lamp output: UVB roughly 280 to 315 nm, UVA roughly 315 to 400 nm, visible red around 630 to 660 nm and near infrared around 800 to 900 nm in red light units. The wavelength of an LED is fixed at manufacture; a fluorescent lamp's spectrum is set by its phosphor.

NEMA receptacle

The standardized outlet and plug pattern, named by the National Electrical Manufacturers Association. 120 volt beds use household 5-15 or 5-20 patterns. 220 volt beds use 6-15, 6-20 or 6-30 straight-blade patterns or an L6 twist-lock, chosen by the bed's amperage. The pattern on the bed's plug tells an electrician the circuit it needs. The spec sheet lists them.

Neutral

The return conductor in a 120 volt circuit. Most 220 volt tanning beds do not use one at all; they run between two hot legs plus a ground. Some beds use a neutral for 120 volt accessories such as fans, audio or a control board while the lamps run on 220. Which arrangement a bed uses is on the data plate and decides whether a three-wire or four-wire circuit is pulled.

O

Overheat shutdown

The bed switching off mid-session, or refusing to start, because a thermal cutoff opened. The cutoff is doing its job; the question is why the temperature rose. In order of likelihood: a clogged air filter, a dead fan, a room too hot or too tight, a ballast running hot. The bed usually restarts after cooling, which hides the fault until it recurs. See fans and cooling.

P

Phosphor

The white powder coating inside a fluorescent tanning lamp. It absorbs the short-wave UV from the mercury discharge and re-emits it at longer wavelengths. The phosphor blend decides the lamp's UVA to UVB ratio and is the only real difference between a standard, a bronzing and a high-UVB lamp. Phosphor degrades with hours, which is the main reason UV output falls while the lamp still looks lit.

Power cord

See cord and plug. The cord is sized by the bed's amperage and is replaced as a complete assembly with its plug when either end is damaged. A cord that is warm to the touch during a session, discolored at the plug or stiff and cracked at the bed entry has reached the end of its service and is a fault to fix before the next session, not after.

Preventive maintenance

The schedule of cleaning, inspection and replacement that keeps a bed out of the repair queue: acrylic cleaning and inspection daily, filters and fans weekly, UV readings and lamp holders monthly, starters at relamp and gas springs on a multi-year interval. The full schedule is in the preventive maintenance guide. Most emergency calls trace to one skipped item on it.

Q

Quartz

The envelope material of high-pressure lamps, chosen because it stands up to the temperature and the metal halide chemistry inside. Quartz transmits UV freely, which is why these lamps always run behind filter glass. Fingerprints on quartz bake in and create hot spots, so these lamps are installed with gloves or a clean cloth and never touched bare-handed.

R

RDC

Recessed double contact, a lamp base with a single recessed metal contact at each end rather than exposed pins. The matching holder presses against the contact, and one holder is spring-loaded so the lamp can be seated. RDC is the usual base on F73 lamps and many 160 watt lamps. RDC and bi-pin lamps do not interchange, so the base type is part of every lamp order.

Red light bed

A bed or booth that uses LED arrays or red fluorescent tubes to emit visible red and near-infrared light instead of UV. Mechanically it shares the tanning bed's cabinet, acrylic, fans, timer and canopy springs, but its light source runs on drivers rather than ballasts and is rated in tens of thousands of hours. Installation and electrical needs are covered at red light bed installation.

Reflector, bed

The polished aluminum or white-coated sheet metal behind the lamps that redirects light that would otherwise go into the cabinet back toward the user. Reflectors dull with dust, heat and cleaner overspray, and a dirty reflector can cost measurable output on a meter. They are wiped at relamp. Beds that use reflector lamps may have no separate reflector at all.

Reflector lamp

A fluorescent tanning lamp with a reflective coating applied inside the glass over part of its circumference, so the lamp aims its own output through the uncoated side. Reflector lamps deliver more light to the user from the same wattage and are specified by some beds in place of external reflectors. They install with the clear side facing the acrylic, and a reflector lamp put in backwards looks fine and performs badly.

Relamp

Replacing every lamp in a bed as a matched set, with new starters where the ballasts use them, a cleaning of reflectors and acrylic, and a reset of the hour meter. Lamps are changed together because a mix of old and new produces uneven output across the body. Timing is set by hours, not burnout; the relamp scheduler works out the date from the bed's usage.

Relay

An electrically operated switch smaller than a contactor, used on control boards and timers to switch fans, facial lamps, cool-down or the contactor coil itself. Relays fail stuck open, stuck closed or chattering, and a relay fault often looks like a board fault. A remote timer's output relay is rated for the contactor coil, not the lamp load, which is why a timer wired straight to lamps burns out.

Remote timer

A timer located away from the bed, usually at a salon's front desk, that starts and stops the bed through a low-voltage control line. The desk unit sends the start signal; a relay at the bed fires the contactor. Remote timers keep session control with staff and log usage. T-Max is the common brand name. Faults are covered on the timers page.

S

Serial number

The unique number on the data plate that identifies one specific bed within a model. Manufacturers changed acrylic sizes, ballast types and timers mid-production without changing the model name, so the serial is often what tells a parts supplier which version you have. Photograph the whole plate rather than copying the model name alone.

Session timer

The device that energizes the lamps for a set number of minutes and shuts them off. It may be an in-bed timer on the bed or a remote timer at a desk, and its maximum setting cannot exceed the bed's exposure schedule. A timer that counts but produces no light is passing the fault downstream to the contactor. See timer not working.

Shocks

The everyday name for gas springs, the struts that hold a canopy open. The word comes from their resemblance to automotive shock absorbers, but they are not interchangeable with anything from a car; they are matched by length, force rating and end fitting to the canopy they hold. A lid that drifts down, slams or needs a push to open is a shock set at end of life. Sourced on the gas springs page.

Single-phase power

The type of electrical supply in homes and most small commercial spaces, and what nearly all tanning beds are built for. A 220 volt bed runs across two hot legs of a single-phase service. Buildings with three-phase service can feed a bed from two of the three legs, but the resulting voltage may be 208 rather than 240, which is where a buck-boost transformer comes in.

Starter

A small twist-in component paired with each magnetic ballast. It closes briefly to preheat the lamp's electrodes, then opens, and the voltage kick from the ballast strikes the lamp. Starters are the cheapest part in the bed and the first swap when a lamp flickers at the ends or will not light. They are replaced at every relamp. See starters and lamp, ballast or starter.

Starterless ballast

A ballast that strikes the lamp without a separate starter, either by preheating the electrodes itself (rapid start) or by applying a high voltage directly (instant start). All electronic ballasts are starterless. On a bed with no starter sockets, a lamp that will not strike is a lamp, holder or ballast question with no cheap first swap available.

Strike

The moment a discharge lamp lights, when the gas inside becomes conductive and current begins to flow. A healthy fluorescent lamp strikes within a second or two; a healthy high-pressure lamp takes longer and comes up to full output over a few minutes. Slow striking, repeated attempts or flashing at the ends point to a weak starter, a tired ballast, low line voltage or a lamp near end of life. See lamps dim or flickering.

Surge protection

Devices that clamp voltage spikes from the utility or from lightning before they reach the bed. Electronic ballasts, LED drivers and control boards are the parts a surge takes out, and they are the most expensive and the hardest to source. Whole-panel surge protection installed by an electrician is more useful than a plug strip, which is not rated for a bed's current in any case.

T

T-diameter (T12, T8, T5)

The tube diameter code in a lamp code, in eighths of an inch. T12 is 1.5 inches and is the standard tanning lamp diameter. T8 is one inch and T5 is five-eighths, both found in some facial positions and compact beds. Diameter has to match the holder spacing and the ballast rating, so a T8 lamp cannot simply stand in for a T12 of the same length.

T-Max

A brand of remote timer systems made by Applied Digital, so common in salons that the name is used for the whole category. A typical setup pairs a desk controller with a timer module at each bed, linked by low-voltage cable, with an output relay at the bed that fires the contactor. Faults divide into desk unit, cable and bed module. Described generically here; the manufacturer's manuals cover specific models.

Terminal block

A strip of screw or spring terminals inside the bed where incoming power, ballast leads, fan wiring and control lines are joined. It replaces a tangle of individual connectors with a labeled row. Loose terminals heat up, discolor and eventually arc, producing intermittent faults that come and go with vibration. Tightening terminals is part of any electrical service visit.

Thermal cutoff

A temperature-sensitive switch or thermal fuse, mounted on a ballast tray or in the canopy, that opens the circuit when the area around it gets too hot. Some reset themselves after cooling; others are one-time devices that must be replaced. A tripped cutoff causes an overheat shutdown. The cutoff is rarely the fault; the fan, filter or ballast that let the heat build is.

Transformer

A component that changes voltage. In a bed, a small step-down transformer feeds the control board, timer and relays at 12 or 24 volts; a larger buck-boost may sit in the supply line to correct building voltage. A dead step-down transformer produces a bed with no display and no response, which is often misdiagnosed as a dead board. Both are sourced through electrical parts.

Tube

The everyday word for a fluorescent tanning lamp, from its shape. Technicians say lamp; salon owners say bulb or tube; all three mean the same part. A tube is specified by its full lamp code, never by appearance, because two tubes that look identical can differ in wattage, base and spectrum. See the lamps page.

Twist-lock plug

A plug and receptacle pattern, designated L in the NEMA system, that locks with a quarter turn so it cannot pull out. Commercial beds and booths often ship with an L6-20 or L6-30. Twist-locks are more reliable under vibration and in salons where carts and cleaning equipment move around a bed, and an electrician needs to know in advance that the bed uses one.

U

UV meter

A handheld radiometer that reads irradiance in a UVA or UVB band through a sensor held against the acrylic. It is how a technician confirms a relamp, finds a weak ballast by comparing lamp positions, and decides when lamps are due before they look dim. Readings only mean something against the same bed's baseline taken at the same spot, and sensors themselves drift and need periodic calibration.

UVA

Ultraviolet A, the band of wavelengths from roughly 315 to 400 nanometers. It makes up the large majority of the output of every fluorescent tanning lamp and nearly all of the output of a filtered high-pressure lamp. On a lamp spec sheet UVA is the balance after the UVB percentage. It is defined here as a measurement band; a UV meter with a UVA sensor reads it directly.

UVB

Ultraviolet B, the band from roughly 280 to 315 nanometers. Tanning lamps are classified by their UVB share of total UV, printed as a percentage on the lamp or spec sheet. Matching that percentage is part of choosing an equivalent lamp, and changing it changes the bed's exposure schedule. UVB is measured with a meter fitted with a UVB sensor.

UVC

Ultraviolet C, wavelengths below about 280 nanometers. The mercury discharge inside a fluorescent lamp produces short-wave UV in this range, but the phosphor coating converts it and the glass absorbs what remains, so a tanning lamp emits essentially none. The same holds for high-pressure lamps behind intact filter glass, which is one reason a cracked filter takes a facial out of service.

V

Ventilation

The room's ability to carry away the heat a bed produces, which is roughly its wattage: a 3,000 watt bed is a 3,000 watt heater while it runs. Bed fans move air through the cabinet, but the room has to move that air out. Closed rooms, low ceilings and summer afternoons are where overheat shutdowns and short lamp life cluster. Ventilation is part of every install assessment.

Virtual repair session

A video call in which a technician diagnoses a bed by watching it on the owner's phone: the display, the sounds at startup, the lamp ends, the inside of the ballast tray. Most faults in the diagnostic sequence can be identified this way and the right part shipped. It is how salons without a local technician get service. See virtual tanning bed repair.

Voltage (120 versus 220)

The supply voltage a bed is built for, on the data plate. Small home beds run on a 120 volt household circuit. Most salon beds and larger home beds need what owners call 220, which in a US building is nominally 240 volts across two hot legs. A 220 volt bed cannot be adapted to 120, and running either bed on low voltage dims lamps and stresses ballasts. See electrical requirements.

W

Wattage

The power rating of a lamp, most often 100 or 160 watts for body lamps and higher for high-pressure units, printed in the lamp code. Wattage is tied to the ballast: a lamp of the wrong wattage may light but will underperform or fail early and can damage the ballast. The bed's total wattage, lamps plus ballasts plus fans, is what sets its amperage and the heat it puts into the room.

Wire gauge

The conductor size of the circuit feeding the bed, chosen by the breaker rating and run length. In US practice a 20 amp circuit is wired with 12 gauge copper and a 30 amp circuit with 10 gauge; longer runs may step up a size to limit voltage drop. Undersized wire runs warm and drops voltage, which the bed shows as dim lamps and slow strikes. Listed on the electrician spec sheet.

Wiring harness

The bundled, pre-terminated wiring that connects ballasts, lamp holders, fans, timer and contactor inside the bed. Harnesses are model-specific. Insulation hardens and cracks at the hot end of the ballast tray, connectors loosen with heat cycling, and a chafed harness is a common cause of a fuse that keeps blowing. Repairs are made with matching gauge and heat-rated wire; a harness is replaced whole only when the damage is widespread. See electrical parts.