4387535 â¤Whirlpool â˘Refrigerator⢠Compressor relay And Overload Start âKit is⢠a combined electrical start relay⤠and thermal âoverload protector â¤supplied for use on singleâphase hermetic â¤refrigerator compressors. The assembly is a control âŁcomponent⤠that helps initiate compressorâ motor startup and provides thermal/current âprotection â¤during operation;⣠it â¤typically⤠contains⣠a⤠relay â˘element (or PTC device) â˘toâ engage⣠the compressor start circuit and âan overload heaterâ or thermostat that opens⢠the circuit under excessive temperature or current conditions.
Inside⣠the appliance the startâ kit⣠interfaces directly with the compressor motor terminals⤠and the refrigerator’s power/control wiring. During a start event the relayâ portion provides theâ necessary change âin the motor circuit to â˘produce start torque for theâ compressor start winding, â¤and once⢠the motor âreaches running⣠speed the relay removes âthe start âpath. The overload element monitors motor temperature/current andâ interruptsâ power⤠if the compressor experiencesâ sustained âovercurrentâ or overheating,⤠preventing⢠further damage.This component therefore âinteracts with the compressor itself,⤠the incoming mains â¤power, the thermostat/control board that âŁcommands compressor run cyclesand âany lineâprotection devices upstream.
In this âarticle readers will find a technical examination â¤of âŁthe 4387535 â˘start kit including howâ it functions⢠in the âcompressor âstart/protection circuit, typical electrical andâ mechanical compatibility âŁconsiderations, common failure symptoms (for example â¤compressor hum without â˘start, repeated âtripping, âŁor intermittent âoperation)and practical troubleshooting checks a âtechnician can use⢠(visual â˘inspection, terminal and continuity checks,⣠and current/voltage observations). The piece â˘will also cover replacement â˘considerations such as matching terminal arrangement âŁand ratings, mounting âŁandâ wiring details, âand⢠safety precautions to observeâ when âdiagnosing or replacing the component.
Tableâ of Contents
- Function â¤and Role of the Compressor Relay⤠and Overload âStart Kit â¤in Refrigerator Compressor⣠Control
- How the âŁ4387535 Whirlpool Refrigerator Compressor Relay And⤠Overload Startâ Kit Operates Within â˘the Appliance Starting âŁandâ Protection Circuit
- Commonâ Failure Symptoms⢠and â˘Electrical Diagnostics for a Defective Relay/Overload â˘Start Kit
- Compatibility, Replacement Considerations,â installation Best Practicesandâ Troubleshooting Procedures
- Q&A
- Wrapping Up
Function and Role âof the Compressor Relay and overload⣠Start Kit in âRefrigerator Compressor⤠Control
The 4387535 âŁWhirlpool Refrigerator âCompressor Relay And Overload Start⣠Kit provides theâ two basic electrical functions required âto â˘startâ and protect aâ hermetic refrigerator compressor: âa start relay âthat âŁmomentarily âconnects the⣠compressor’s start âwinding â¤or âa start device while the motor acceleratesand âŁa thermal overload that interrupts current if the compressor draws excessive amperage or overheats.The relay closes â¤for a short âinterval during âinitial energization⤠to provide the necessary torque; once the compressor âreachesâ operating speed the relay opens and the motor runs⢠on the⤠run winding. The overload â˘is a current- or temperature-sensitiveâ protector â¤mounted on the compressor â¤terminals⤠that opens under sustained high âcurrent âor⢠elevated temperature to prevent windingâ damage and⣠motor âŁburnout.
In practice, technicians diagnose failing â˘relays and âoverloads byâ symptoms such as repeated humming âwithout rotation, long crank âtimes, âŁor a compressor that starts âŁintermittently and âthen trips out. Before replacement, confirm terminal⣠layoutâ and electrical ratings match â¤theâ compressor nameplate; improper relay âŁcharacteristics or â¤miswired⤠terminals can âprevent â˘starting or⢠cause âŁnuisance trips. Typical field checks include listening for theâ relay click on⢠power-up,⤠measuring continuity betweenâ compressor â¤terminalsand verifying that the âoverload opens when âheated and⤠resets âwhen cooled.â Commonâ troubleshootingâ and practical notes:
- Symptoms: humming butâ no start, frequent âŁcyclingor immediate trip on energization.
- Compatibility checks: match terminalâ arrangement (Common-Start-Run) and voltage/current ratings⣠to the compressor nameplate.
- Installation: disconnect⢠mains, transfer all terminals exactlyand ensureâ secure⣠spade connections to â¤avoidâ added resistance and heat.
| Item | Description |
|---|---|
| Start⢠Relay | Providesâ momentary connection â˘to the start winding or engages a â˘start deviceâ to develop starting torque. |
| Thermal Overload | Opens the circuit⣠under⣠sustained overcurrent âor high temperatureâ to protect the compressor motor. |
| Terminal Layout | Common (C),⣠Start⢠(S), run (R) – verify â¤beforeâ installation. |
| Failureâ Indicators | Humming without start, long crankâ timesor â¤immediate trip â¤upon⤠energizing. |
How the 4387535 Whirlpoolâ refrigeratorâ Compressor Relayâ And Overload Start Kit Operates Withinâ the Appliance Starting⤠and Protection â˘Circuit
The 4387535 Whirlpool Refrigerator âŁCompressor â¤Relayâ And Overload Start kit performs two coordinated âelectrical functions in the appliance starting and protection circuit: it supplies â¤momentary current to the compressor’s ⤠start âwinding to produce theâ necessary torque for startupand âit isolates the compressorâ from âmains âŁpower⤠when the motor âdraws excessive âŁcurrent or⤠overheats. Whenâ the⤠thermostat closes âand mains voltage is applied, the âŁrelay element closes (or presents low resistance) âto the⣠start terminal, allowing âthe âstart coil⤠to contributeâ torque; after the â¤compressor reaches near ârunningâ speed the relay opens âand the â¤motor continues on the run winding. The overload protector is aâ temperature- and current-sensitive device placed in series with the common terminal, opening under sustained high current or thermal stress â˘to prevent coil damage and to allow timeâ for cooldownâ before automatic or manual reset, depending on theâ design.
Technicians diagnose relay and overload behavior by observing startup symptoms and performing simple electrical checks: intermittent clicking â˘with âŁno start, long humming with high⣠current drawor anâ open-circuit on âthe overload areâ common âŁindicators of failure.â Useful checks include verifying continuity across the run and âstart paths, measuring resistance⤠values against compressor specifications, âŁand checking that the relay switchesâ out âthe start path within⤠a⣠fraction of aâ second after startup. Practical âcompatibility considerations include matching⢠terminal layout, mounting styleand rated current and trip characteristics to the compressor model; incorrect⤠substitution can allow repeated nuisance trips or fail toâ provide⢠adequate starting torque. Typical functionalâ aspects to be awareâ of are listed below.
- Momentary⣠connection of startâ winding âŁduring initialâ motor acceleration
- seriesâ thermal/current overload that opens under fault conditions
- Physical and⤠electrical matchâ required⢠forâ reliable operation
| item | Description |
|---|---|
| Startâ Relay | Applies andâ then⢠removes the starting current to the start winding during motor spin-up |
| Overload Protector | Opens âthe compressorâ common to interrupt supply when âcurrent â˘or temperature exceeds âŁsafeâ limits |
Common Failure Symptoms and Electrical Diagnostics for a Defective Relay/Overload Start Kit
The 4387535 Whirlpool Refrigerator Compressor Relay âAnd Overload Start âŁKit combines â˘a start ârelay – âŁwhichâ momentarilyâ connects the âŁcompressor’s start winding to produce the âinitial torque â- with a â¤thermal/magnetic â˘overload that opens under â¤sustained overcurrent⣠or overheating. In normal⤠operation theâ relay provides aâ brief conduction â¤path from âthe line âto âthe start terminal âwhile the run winding carries the steady-state load;⤠the overload sits in series with â¤the compressor common⤠to interrupt current if the compressor⣠stalls âŁorâ draws excessive amps. Compatibility is determinedâ by theâ compressor terminal arrangement (C, R, S) andâ the kit’s mechanical/terminal form factor, so technicians should confirm fit â˘against âthe compressor⤠shell and service manual before replacement.
Typical symptoms â¤of a failing relay/overload âŁare predictable âand⣠canâ be isolated withâ simple electrical checks. Common⤠fieldâ indicators include:
- Hummingâ sound âfrom theâ compressor without startupâ and â¤the refrigerator⢠failing to cool.
- Repeated click âŁattempts as theâ relay cycles and the compressor never âreaches running speed.
- Compressor becomes unusually â¤hot âto the touch â˘orâ trips the thermal cutout repeatedly.
- High measured current on the⤠compressor circuit at start (inrush) or frequent⣠thermal trips during run.
Diagnostics start with power removed: inspect⤠the relay for â¤burnâ marks or âswelling, then⢠measure âŁcontinuity across⣠the overload (should be âclosed at ambient) and acrossâ theâ relay contacts â¤between the start and common terminals when the unit is stationary. Withâ power applied and appropriate⣠safety⣠precautions,â observe voltage at⢠the run and start â terminals during a start âattempt – the run âterminal will see⢠steady âline voltage âwhile the âstartâ terminal should see a âmomentary pulse âŁif the relay engages.Use â˘a clamp ammeter to compareâ inrush to expected values and, whenâ possible, swap â¤in â¤a known-good relay/overload toâ confirm behavior âŁbefore replacing the compressor. The tableâ below âsummarizes the swift reference âchecks technicians use âon site.
| Item | description |
|---|---|
| Overload continuity | Should â¤read closed (lowâ resistance) at ambient;⢠opens when âŁoverheated or after sustained overcurrent. |
| Relay function | Providesâ brief âconduction â˘to the start winding⣠during startup; failureâ frequently⤠enough shows noâ continuity to start or a welded contact. |
| Terminal IDs | C =â Common, R â = Run, S =â Start – â¤verify wiring and mechanical fit for âcompatibility. |
Compatibility, âŁReplacement Considerations, â˘Installation Best Practicesand Troubleshooting Procedures
The 4387535 Whirlpool Refrigerator Compressor Relay And Overload Start Kit functions as the âelectrical interface that âallows a singleâphase hermetic compressor â¤to reach the torque necessary to start. The kit replaces theâ compressor’s external start â¤relayâ and â˘thermal overload protector; compatibility depends on matchingâ the compressor’s⢠terminal arrangement and electrical ratings. Beforeâ replacing the module, verify the âcompressor ânameplateâ for rated voltage âand â˘lockedârotor/ running amperage and confirm the terminal â˘configuration-most⤠compressors use S, R, C terminalsâ while some systems use a twoâterminal âarrangement with⣠an internal start âdevice. Physical fit, connector styleand⣠the overload⢠tripâ characteristics âmust be compatible with â¤the compressor and cabinet layout toâ avoidâ nuisanceâ trips⤠or an âinability⣠to âstart under normal loadâ (for⣠example, aâ relay designed âfor a much lower RLA can allow âthe compressor to stall under high starting torque conditions). OEM kits like â¤this one are designedâ to matchâ the original protective â˘characteristics,â butâ checking the service manual or âcompressor datasheet before replacementâ provides a practical safeguard âagainst mismatches.
For installation and troubleshooting, âŁalways disconnect power and â˘confirm â˘no capacitor charge remains before handling electrical components. Basic diagnostic âsteps include visual inspection for heat damage or⣠melting, verifying⤠continuity across âtheâ overload and relay terminals with a multimeter, âand measuring inâcircuit starting current where⣠appropriate; â¤a humming compressor that does not run âŁor frequent short run âcycles commonly indicatesâ aâ failed relay/overload. Secure the â˘kit to the cabinet âŁso the âthermalâ protector âsenses cabinet temperature correctly, route wiring away from sharp edges âand hotâ surfacesandâ torque fasteners to the manufacturer’s recommendations to avoid creating electrical⣠or âthermal faults.Commonâ symptoms and quick â˘checks:
- Compressor hums but won’tâ start – check relay âcontinuity â¤and lockedârotor amperage.
- Compressor âŁstarts then quickly stops – test overload continuity and inspect for intermittent connections.
- Burnt connectors⢠or discolored housing⤠– replace kit and repair harness to ârestore reliable thermal sensing.
| Item | Description |
|---|---|
| Terminal âids | S â (Start), ⢠R (Run), C ⤠(Common) – matchâ wiring harness âŁaccordingly |
| Voltage | Match âkit⢠rating⣠to refrigerator line voltage (typically 115-120 â˘V in Northâ American models) |
| Failure indications | Humming/noâstart,â rapid âcycling, high starting current; verify with inâline ammeterâ and continuity checks |
Q&A
What is⤠the 4387535 Whirlpool âRefrigerator Compressor Relay âand Overload Startâ Kit?
The 4387535 kit is⢠a replacement âcompressor start assembly⢠that typically contains aâ start relay (or âPTC relay) and an⢠overload âprotector. It helps â¤the refrigerator compressorâ start⣠and protectâ it from excessive â¤current or overheating. It is a common service part for many Whirlpool/Maytag/Kenmore refrigerationâ modelsâ that use a singleâphase compressor.
what symptoms⢠indicate the â˘start kit â(4387535) â˘might âbeâ bad?
Common symptoms include: compressor not starting but humming or clicking, repeated âattempts to start (rapid clicking), fridge not cooling âwhile âfans run,⤠or âthe compressor hot to the⣠touch. If the overload or relayâ is open or â¤failing, âthe compressor may not receive â¤the⣠start âŁkick and will⢠either ânot run â˘or will trip the âoverload repeatedly.
How do I âverify â¤the 4387535â start kit is the⣠problem before replacing it?
First unplug the refrigerator for safety. inspect the relay/overload forâ physical⢠damage, melting or burn âmarks. âWith the⢠kit âŁremoved, âŁcheckâ continuity: the overload protector âŁshould show continuity when cold; a wholly open circuit suggests a bad overload. Aâ PTC start relay is âharder toâ bench-testâ with simple⢠tools-common checks are visual inspection, substitution with a known-good relayor listening for â¤the compressor attempting âto start⢠when theâ relay is connected. If the compressor is seized or the⣠sealed âsystem âhas a fault, replacing the relay⢠may not fixâ the âissue.
How â¤do â˘I â¤replace the 4387535 relay⢠and overload kit?
Turn off power âto â¤the refrigerator â(unplug or switch off breaker).Access the â˘compressor⤠at the rear âlower⤠panel, remove the relay/overload from âthe⤠compressor terminals (usually âa clip-on â¤assembly or push-on terminals). Disconnect the old unit and connect⣠the new⤠kit inâ the same orientation, ensuring firm terminal connections and that the âoverload isâ properly seated against the â¤compressor body â˘(if designed that way). Restore power and observe operation. If unsure,â consult the refrigerator’s âservice manual orâ hire a qualified technician.
Will installing the 4387535 kit fix⣠a locked âor damaged compressor?
No. The startâ kit helps start âa⣠properly functioning compressor. â¤If the compressor is mechanically⣠locked, seizedor⤠internally⣠damaged, replacing the â˘start kit will not make itâ run â¤and may causeâ repeated⣠failures.If the compressor âdraws very highâ currentâ or shows â˘no rotation when power is applied, the âcompressor⤠itself or the sealed system may ârequire repair âor replacement.
Is theâ 4387535 kit compatible with my Whirlpool/maytag/Kenmore refrigerator?
Compatibility depends on â˘your refrigerator model and compressor type. Many Whirlpool/Maytag/Kenmore models⣠use this or âequivalent start â˘kits, âbut âŁyou should confirm by checking your appliance model number and crossâreferencing parts lists fromâ the manufacturer or a reputable⤠parts supplier. Do⢠notâ rely⣠solely onâ visual âŁmatch-verify compatibility with model/part â¤crossâreference details.
What tools and safety precautions âŁdo⤠I need⣠to⣠replace âthe start kit?
Tools: basic hand âtools âŁto remove the rear access panel (screwdriver, nut driver), needleânose pliers mayâ help with terminals. â¤Safety: disconnect power before working, avoid⤠shorting terminals, allow components to cooland avoid touching â˘refrigerant lines. If⤠the appliance⢠has a start â˘capacitor (rare on small âfridge compressors),⣠discharge it before handling. âIf you are not pleasant working on electrical âcomponents, âhireâ a âqualified appliance technician.
How much does aâ replacement 4387535⤠kit cost andâ is âthere any warranty?
Price varies by â˘supplier but⢠these start/overloadâ kits are generally inexpensive âcompared with compressor replacement. âMany âparts⣠suppliers and manufacturersâ offerâ limited warranties âŁon replacement parts-check theâ seller’s return and warranty policy⢠before purchase. If the compressor fails⣠soon after âŁinstallation, save receipts and document the issue for warranty or professionalâ diagnosis toâ determine â˘if âŁthe fault âis â˘with the kit or â¤the â¤compressor.
Wrapping â¤Up
The â4387535 Whirlpool Refrigerator Compressor Relay and Overload Startâ Kit plays a critical role in initiating and protecting the compressor motor, enabling reliable⤠start-upâ and guarding against electricalâ overloads and thermal stress.By ensuringâ the âŁcompressor receives the correct starting current and by⢠interrupting power duringâ abnormal operating âconditions,⤠this kitâ helps maintain cooling âperformance, improve â˘energy⢠efficiencyand reduce âtheâ risk âof compressor damage that â˘can lead⣠to costly repairs âor premature failure.
Accurate âdiagnosis is â¤essential âwhen troubleshooting starting or cooling issues:⢠symptoms âŁsuch as â˘repetitive⢠clicking,â a warm refrigeratoror â˘a humming compressor⤠can indicate ârelay or⣠overload problems but⤠may also result from otherâ system âfaults. Verifyingâ the condition of the ârelay and overload with proper testing procedures, âreferencing model compatibility âfor part âŁ4387535andâ distinguishing⢠electrical faults âfrom refrigerant or mechanical issues⤠will â˘help determineâ whether replacement is â˘necessary andâ appropriate.
When replacement â˘is justified, usingâ the correct part and⤠installing itâ according toâ manufacturer guidelinesâ helps restore â¤reliable operation and prolong⢠equipment life. Ifâ there is⣠any uncertainty about diagnosis or safeâ installation,engaging a qualified⣠appliance⤠technician ensures âthe repair is⤠performed correctly and safely. Timely,well-informed action-diagnosis,correct âpart â˘selection,and professional installation when⢠needed-offers the best âpath to stable performance and long-term value.
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