4387535 Whirlpool Refrigerator Compressor relay And Overload Start Kit is a combined electrical start relay and thermal overload protector designed for use with singleâphase hermetic⣠compressor motors foundâ in⣠household refrigeration units. The assembly typically mounts at the compressor shell âŁor connects directly to⢠the â˘compressor terminals⣠and provides the â˘auxiliary start⢠function plus an âovercurrent/thermal cutout⤠in a compact serviceable module.
Functionally, the relay portion provides a â¤timed⣠or currentâsensing connection to the âcompressor’s start winding to produce the additional torque required toâ overcome lockedârotor conditions at motor start, âwhile the overload element opens the â˘circuit⤠when excessive current⣠or temperature indicates motor âstress or â˘a fault. The kit interfaces with the⤠compressor start⣠and run windings, âthe incoming line supplyandâ the appliance’s control circuitry; its behavior affects compressor start â˘performance, running stability and protection against sustainedâ overcurrent or overheating that â˘could damage the sealed refrigeration system.
In this article you will find âŁa technical overview⤠of how the â4387535⢠start â¤kit operates, guidance on âŁmodel compatibility and â˘electrical⤠ratings⤠to check before replacement, common failure symptoms (such as humming/noâstart, repeated cyclingor visible overheating), practical troubleshooting âsteps⣠including continuity and âwinding resistance checks and inâcircuit current observationsand⣠replacement considerations⤠such as connector â¤type, âmounting orientationand safety⤠precautions. The âfocus isâ on⣠providing technicians,â engineersâ andâ applianceâ owners⤠with the â¤information needed to diagnose startâcircuit issues and to select and install⤠an⣠appropriate replacement without prescriptive marketing â˘claims.
Table of⤠Contents
- Function and â˘Role âof the â¤Compressor Relay and Overload Start Kit⢠in Whirlpool Refrigeration⤠Systems
- How the 4387535 Whirlpool Refrigerator⣠Compressor relay And Overload Start Kit Interfaces with âthe Compressor â˘Motor and Control Circuit
- Common failure Symptomsâ and Electrical Indicators⤠of a Defective Relay/Overloadâ Start⤠Kit
- Replacementâ Considerations and StepâbyâStep âInstallation procedure âŁfor â¤the Relay and Overload âŁStart Kit
- Q&A
- Key Takeaways
Function and Roleâ of the âCompressor â¤Relay⢠and Overloadâ Start Kit in Whirlpool Refrigeration Systems
The 4387535â Whirlpool Refrigerator Compressor Relay And âOverload Start âKit⢠combines a start relay and a â˘thermal overloadâ protector toâ manage âthe compressor’s âstart-up and protect the⤠motor during operation. â˘Theâ start relay momentarily connects the compressor’s⤠start winding to produce theâ extra â¤torque â˘needed to spin the â˘compressorâ motor from standstill, while âthe âŁoverload âdevice interrupts current if the motor draws âexcessive current or⣠reachesâ a high temperature.In many whirlpoolâ applications this kit replaces the factory â˘relay/overload âassembly andâ is designed to interface with singleâphase hermetic compressors that use distinct start and run windings;â the relay can be âa PTC orâ voltageâsensing⢠type dependingâ on the âcompressor design,and the overload is typically a bimetal/thermal protectorâ placed in series âwith âthe â˘compressor windings.
- Common failure symptoms: rapid clicking,a humming â˘compressor that does not start,repeated start attempts⢠followed by âlong off periods,or a relay that isâ physically hot orâ discolored.
- Compatibility⤠cues: âŁmatch terminal labels (C, â˘R,⢠S), âverify nominal âsupply voltage⤠(usually 115 VAC âin âhousehold units),â and âconfirm â¤mechanical mounting âand connector type against the OEM bracket.
- Practical check: a relay that permits start voltage to the start winding and an overload that shows â¤continuityâ when cold are âŁbaseline tests; a clamp meter to measure starting current can confirm excessive draw indicative of a failing relay or compressor.
Technicians should â˘verify wiring⢠and terminal orientation⤠before installation and isolate⤠powerâ prior to testing. For troubleshooting, measure supply⢠voltage at the compressor terminals during a start attempt âand compare observed starting current against manufacturer service âdata; a functioning relay will apply start windingâ voltage only⤠for âŁa short interval and the overload will remain closed unless overheating or sustained⤠overcurrent occurs. Replacement withâ the correct 4387535 kit â˘or equivalent shouldâ restore proper start sequencing if the compressor motor is or else healthy, but persistent high starting current or locked rotor⣠conditions indicate internalâ compressor faults rather than relay/overload failure and require compressor-levelâ diagnostics or replacement.
| Item | Description |
|---|---|
| Function | Relay: engage start winding briefly; Overload: open⤠circuit â¤on overcurrent/overheat |
| Typical Voltage | Household âŁAC⢠mains, commonly â115 VAC⤠(verify âappliance rating) |
| Terminal IDs | Common (C), Runâ (R), Start âŁ(S) – confirm before wiring |
How⢠the 4387535 Whirlpool Refrigerator Compressor Relay And âOverloadâ Start Kit Interfaces with âŁthe Compressor Motor â˘and⢠Control Circuit
The 4387535 Whirlpool Refrigerator Compressor Relay And Overloadâ Startâ Kit provides the electrical interface âbetween âŁthe refrigerator control circuit and âthe compressor motor by combining âa â¤start-relay element with âa series overload protector. The relay element momentarily connectsâ the compressor’s startâ winding to mains â˘during⤠initial spin-up (typically by switching a PTC/resistive element or âa mechanical contact), than âŁdrops out onceâ the motor reaches operating speed;⣠the overload device is wired in series with the compressor common â¤and opens⢠on sustained overcurrent or âŁexcessiveâ internal â¤temperature to protect the motor. In practical installations the kit mounts to â¤the compressor terminal block (Common,Start,Run) and must match the â¤compressor’s terminal â˘layout and⤠voltage/current ratings to ensure âcorrect start timing and thermal protection-suchâ as,replacing a failed OEMâ start relay on a Whirlpool cabinet where⣠the compressorâ hums but does⤠not⣠develop sufficient torque toâ start â˘after âa defrost cycle.
In ânormal operation the refrigeratorâ control âboard supplies line voltageâ to the compressor circuit âbut relies on the start kit⤠to provide the transient â˘start-phase behavior; the ârelay element either senses motor backâEMF orâ relies on âitsâ intrinsic time/temperature âcharacteristic toâ remove start assistance âonce the ârun windingâ carries the âload.The overload remainsâ continuously⤠in seriesâ with the common âterminal and will âshow âcontinuity cold and open â˘under thermal âstress, which âŁtechnicians use forâ diagnostics. Typical interface symptoms thatâ point to the relay/overload interaction includeâ repeated â˘clicking at start,prolonged⤠humming without⣠start,or a compressor that starts intermittently after several â¤attempts-these indicate⢠the â˘start device is not providing a stable initial connection â¤or the overload is tripping. â˘for safety âand correct operation always verify terminal⢠identification and voltage before replacing the kit and use âproper measurement techniques when âchecking startâphase voltages â˘and continuity.
- Momentary start âconnection to the start winding (relay/PTC behavior)
- Series⣠thermal/current protection âŁon the common terminal⤠(overload)
- Physical and electrical compatibility â˘with compressor terminal block (C, S, R)
- Diagnostic indicators: clicking, humming,⤠intermittent â˘startsor overload âopens
| Item | Description |
|---|---|
| Common (C) | Line input/output path that includesâ theâ overload; âopensâ when overload trips |
| Start (S) | Terminal⤠that⤠receives the temporary startâ connection âŁfrom theâ relay/PTC |
| Run (R) | Permanent connection â˘to the run winding; carries motor current âŁduring steady â¤state |
Common Failure âŁSymptoms and Electrical â˘Indicators of a Defective Relay/Overload Start âKit
The â¤4387535 âŁWhirlpool Refrigerator Compressor Relay⣠And Overloadâ Start⤠kit combines theâ start relay âŁand thermal overload protector that sequence and âprotect the âcompressor motor duringâ startup. The relay⣠provides â¤the brief âadditional torque or switching path to engageâ theâ start⣠winding, âwhile the â¤overload⤠opens âunder sustained highâ temperature or current to protect the motor windings. âTypical âmechanical failure modes include a welded or pitted relay contact that âprevents the â˘start winding from engaging, a PTC or coil element that no longer changes resistance under loador a⤠thermal âelement that opens prematurely when it⣠reaches operating temperature; â˘each produces distinct behavioral symptoms at the â¤cabinet â˘and â¤the compressorâ terminals. Match the kit⢠to⣠the compressor’s terminal layout and rated coil/current specifications – improper â¤compatibility can result in repeated failed â˘starts or nuisance overload trips even if the compressor itself is healthy.
Technically useful electrical indicators include continuity and resistance measurements across the start and run terminals, voltage present at the âŁstart-leg during attempted startsand inrush/current draw âŁcompared to the compressor’s âlocked-rotor and ârunning-ampâ ratings. Use an AC clamp â˘meter to observe starting current: a persistent low-amplitude hum âwith low inrush usually points to aâ failed start relay â˘orâ open start winding â˘path;⤠high inrushâ that never âtransitions⤠to⤠a normal run current suggests the relay âis ânot withdrawing or the startâ capacitor/starting â¤circuit is shorted.Practical troubleshooting âsteps and common readings⣠include:
- Compressor hums but does⣠not start: no âvoltage âŁat start terminal or open continuity onâ the start relay indicatesâ failed ârelay/PTC or â¤open start winding.
- Rapid â˘clicking or repeated attempts to start: â¤thermal overload cycling open (overload opening under âheat) or relay chattering due to intermittentâ contact.
- high âcontinuous current â˘at startup without âŁtransition to run current: start device not â˘dropping âout⤠or internal motor problem causing high locked-rotor âcurrent.
| Item | Description |
|---|---|
| No start, â˘constant hum | Start circuit not engaging; check continuity of⢠start relay and voltage âŁon start leg during attempt. |
| clicking and shutoff | Overload protectorâ opening or relay âfailing under⤠load-measure coil/overload resistance cold and hot ifâ possible. |
| Excessive starting amps | Compare measured inrush to âŁcompressor specs; âsustained âhigh amps indicateâ start device failure or internal⤠motorâ fault. |
Replacementâ Considerations and StepâbyâStep Installation procedureâ for the Relay and⤠Overload Start Kit
Theâ 4387535 Whirlpool Refrigerator Compressor relay And âOverload Start Kit is⣠a âŁcombination of â¤a start relay and a thermal â¤overload protector designed to â¤manage the compressor’s startup â˘sequenceâ andâ protect the motor â˘from locked-rotor and overâtemperature âconditions. The start relay âmomentarily energizes the compressor’s⣠start winding (or engages the start circuit) toâ provide the torque needed to spin â˘the rotor, while the overload â˘opens the circuit if current âŁor internal â˘temperature â˘exceedâ rated⤠limits;â proper replacement requires matching terminal labeling, clip/mount âstyleand voltage/current ratings to the compressor specified on the⤠unit nameplate.A common symptom ofâ relay or⤠overload â¤failure is a compressor that hums without â¤starting â¤or âthat requires multiple manual resets; comparing terminal markings (C, S, R) and verifying â˘physical fit prevents mismatches that could lead to repeated startâ failures orâ nuisance trips.
Verify compatibility, â˘perform basic electrical⢠checksand follow safe handling practices â¤before⤠installing the kit. Follow these primary steps for safe replacement:
- Disconnectâ power â¤at⢠the breaker to eliminate shock⤠risk and allow âŁcapacitors (if present) to â¤discharge.
- Remove âthe refrigerator access panel and locate the compressor;⣠photograph the wiring⢠and⣠terminal â¤layout⢠before disconnection.
- Remove the old ârelay/overload assembly fromâ the â˘compressor âterminalsâ and mounting clip,â then compare âŁthe new kit’sâ terminals âand ratings to⤠the removed âparts.
- Install the new relay and overload on the âcorrespondingâ terminals (C,S,R),secure⢠the⤠mounting âclip,and reassemble âthe âaccess panel.
- Restore power and observeâ the start cycle:â the compressor â¤should engage within a few seconds and the âŁrun current should be within the manufacturer’s specified range; if the unit fails to start or trips, re-check terminal connections and part compatibility.
| Item | Description |
|---|---|
| C | Commonâ terminal – âshared return for â˘run and start windings |
| S | Start terminal – connects to startâ winding or start circuit |
| R | Run terminal – main run windingâ supply |
Q&A
What is the Whirlpool 4387535 compressor relay⤠and overload start kitand what parts areâ included?
Theâ 4387535 is an OEM start âŁkit sold for many Whirlpool-family refrigerators. â¤It contains the compressor⢠start device(s) used at â¤the compressor electrical terminals⤠– typically a start relay (PTC or electronic) and an overload protector. These âcomponents help provide âthe extra torque â˘needed âto start âthe compressor motorâ and⢠protect it from overheating.â (Itâ does not include the compressorâ itself âor âany refrigerant-related parts.)
Howâ do I knowâ if âmy refrigerator needs this start kit?
Common symptomsâ ofâ aâ failedâ start relay/overload include: compressorâ humming but not starting, repeated clickingâ as âthe fridge tries to start âand then trips, the compressor runs briefly âthen stopsor âthe⢠fridge is notâ cooling but interior lights and fans work. If you⢠hear a rapid click or observe the compressor⣠trying but not spinning up,a failed âstart â¤kit âis a likely cause. However, sealed-system problems or a locked compressor can produceâ similar symptoms; diagnose carefully before âreplacing parts.
How do I check the old relay/overload âbefore âbuying a replacement?
Frist unplug âthe ârefrigerator â¤and remove the relay/overload from the compressor. â¤Inspect for obvious damage (burn marks, melted plastic, strong burnt odor).⢠Use a multimeter to check âŁfor⢠continuity across theâ overload and between common/start/run terminals whereâ applicable – a completely open circuit often â˘indicates failure. Note that some modernâ PTC/electronic relays do âŁnot give definitive bench readings, so physical inspectionâ and symptom correlation areâ important. Avoid live-jumperâ tests⤠unless you â¤are⤠experienced,â because that can damage the compressor or⣠create safety risks.
Is the 4387535 kit compatible with my Whirlpool/Maytag/Kenmore refrigerator?
Compatibility depends⣠on the refrigerator model⤠and the compressor⣠type. 4387535 fits many⤠Whirlpool, Maytag, KitchenAid and Kenmore models, âbut you should confirm âby checking⢠your⣠appliance model number against a parts lookup or the OEM â˘parts list. Also compare the shape and âŁterminal arrangement âof your existing relay/overload to the replacementâ – âthey must match electrically and physically.When â˘inâ doubt,⤠use the model-basedâ parts lookupâ or contactâ an authorized parts distributor.
How do I install the 4387535 start kit âŁsafely?
Basic safe procedure: disconnect power â˘(unplug or shut off the circuit breaker), pull âthe fridge âaway from the wall,â remove the compressor access panel, carefully unplug the old start⢠kit⣠from âthe compressor terminals âŁ(note orientation and âwire positions),⢠and install theâ new⢠relay/overload in the same position.⣠Reinstall the access â¤panel,restore power,and listen for the âcompressor to start. Do ânot attempt ârefrigerant âwork or⤠open⢠the sealedâ system.If you â˘are not comfortable⢠working on âelectrical⢠components, hire a â¤trained⢠technician.
Will⣠replacing the start kit fix â¤all âno â¤coolâ problems?
No. Replacing the â¤start kit will fix âŁproblems caused by⣠a failed âŁstart relay or overload⢠(inability â˘to start the compressor). âIt will notâ fix sealed-system faults (refrigerant leaks, bad âcompressor motor windings), evaporator/defrost âfailures,⣠or⣠electrical/controlâ board â¤issues. If theâ compressorâ is locked or mechanically failed, a âŁnew start kit will â˘not make it run âand⣠could repeatedly tripâ the overload.
Can I⣠use a worldwide⣠aftermarket start relay instead of whirlpool 4387535?
You can sometimes use a⤠compatible universalâ relay/overload, but you â¤must âmatch the âŁelectrical ratings⢠(voltage, terminal configuration) and ensure physical fit. OEMâ parts are recommended because they âare âmatched âto the originalâ compressor and appliance⣠wiring.If âyou choose a universal part, verify â¤compatibility⣠with your modelâ and âŁcompressor âspecifications to avoid premature â¤failure⢠or⣠improper starting⣠characteristics.
What âŁtools, precautionsand warranty information⤠shouldâ I know before â¤buying and installing this kit?
Tools: basic hand tools (screwdriver, pliers), multimeter for testingand safety gloves. Precautions:â always â¤disconnectâ power âbefore touching â¤compressor terminals, â¤avoid tilting the refrigerator excessively to â¤preventâ oil migrationand do not attempt sealed-system repairs. Warranty:â OEMâ parts typically⤠carry⣠a limitedâ parts⢠warranty â(lengthâ varies by seller); retain proof of purchase â˘and⤠check the⣠vendor or Whirlpool⤠partsâ site⢠for warranty âterms. If the compressor itself⢠is faulty, âreplacing theâ start kit may⤠not resolve the issueâ and warranty coverage mayâ differ for sealed-system components.
Key Takeaways
the 4387535 whirlpool Refrigerator Compressor Relay And Overload Start Kit plays a critical role âin ensuring reliable compressor startup and protectingâ the âŁrefrigerator’sâ refrigeration system⤠from electrical stress. By facilitating the initial motor engagement and âproviding thermal protection againstâ overload conditions, this start kit helps maintain efficient cooling performance, reduces undue âwear on â¤the compressorand contributes to â¤the âappliance’s overall âoperational longevity.
Asâ symptoms of startâ relay or overload failure can resemble other refrigeration problems, âŁaccurateâ diagnosis is essential before replacing components. Whenâ replacement isâ required, choosing â¤the correct kitâ and following appropriate⣠safety and service procedures-ideally performedâ by a qualified technician-helps restore dependable operation and avoid unneeded expense. Regular inspectionâ and timely replacement when â˘faults âŁare confirmed will⤠support continued performance and help prevent more extensive compressor damage.
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