297237702 Frigidaire Refrigerator Start Relay is a compressor start relay specified for certain Frigidaire household refrigeration units. It is a short-duration switching device-either electromechanical or solid-state in design-that provides the auxiliary starting boost to a single‑phase compressor motor by momentarily engaging the start winding (or modifying circuit impedance) to develop the torque required for initial rotation.
within the appliance the start relay works in series with the compressor motor and in conjunction with the compressor overload protector and the refrigerator control/thermostat. During startup it redirects current to the compressor’s start circuit, then drops out once the motor reaches operating speed; it therefore directly affects inrush current, starting torque and the timing of the start sequence. The relay is typically mounted at or near the compressor terminal block or integrated into the compressor wiring harness, and its electrical characteristics must match the compressor and supply conditions to avoid repeated hard starting, excessive heat, or nuisance overload trips.
This article explains the 297237702 part’s intended function and typical construction, how to determine compatibility with a given compressor and model, common failure symptoms to watch for, and the basic diagnostic checks a technician or informed appliance owner can use to isolate relay-related faults. it also covers practical replacement considerations such as matching electrical ratings and connector types,and safety precautions to observe when performing relay replacement or verification.
Table of Contents
- Function and Role of the Start Relay in Compressor Motor Operation
- How the 297237702 Frigidaire Refrigerator Start Relay Works Inside the Appliance
- Common Failure Modes and Diagnostic Symptoms of the Start Relay
- Troubleshooting Procedures and Electrical tests for Start relay Diagnostics
- Q&A
- Concluding Remarks
Function and Role of the Start Relay in Compressor Motor Operation
The 297237702 Frigidaire Refrigerator Start Relay provides the short-duration electrical path needed to energize the compressor’s start winding and produce the torque required to accelerate the hermetic motor from standstill to synchronous running speed. In typical refrigerator compressors this function is accomplished by a current-sensing or PTC-type relay that closes during initial motor excitation and opens automatically once the rotor generates sufficient back EMF; this action prevents continuous start-winding current and limits heating. The relay operates in concert with the overload protector (thermal cutout) and, where present, a start capacitor, so compatibility depends on the relay’s cutout characteristics, terminal configuration, and the compressor’s required start current profile.
Technicians diagnose relay-related faults by observing operational behavior (clicking, rapid on/off cycles, humming or a compressor that attempts to start and then drops out) and by performing basic electrical checks such as continuity and resistance across relay terminals or comparing operation with a known-good unit. Proper replacement requires matching the relay’s electrical switching behavior and connectors to the compressor; an incorrectly specified relay can cause repeated thermal trips or fail to provide adequate starting torque. Practical examples include a refrigerator that repeatedly attempts to start and then trips the circuit breaker (suggesting a stuck-closed or slow-opening relay) or a compressor that never engages the motor (suggesting an open or failed relay).
- Primary functions: energize start winding briefly,then disconnect to protect windings and reduce current draw.
- Common symptoms of failure: clicking, buzzing/humming, repeated attempts to start, or complete inability to start.
- Diagnostic methods: observe behavior during start, check continuity/resistance, and swap with a verified relay when feasible.
| Item | Description |
|---|---|
| Switch type | Typically current-sensing or PTC; opens when motor back EMF indicates sufficient speed. |
| Interaction | Works with overload protector and sometimes a start capacitor to control inrush and runtime during startup. |
How the 297237702 Frigidaire Refrigerator Start Relay Works inside the Appliance
The 297237702 Frigidaire Refrigerator Start Relay controls the short-duration drive to the compressor’s start winding that gets the motor turning from standstill. Inside the appliance the relay provides a high starting torque path-either by closing a low-resistance contact or by presenting a time‑dependent resistance (PTC/solid‑state behavior)-and then removes that path as the motor reaches normal speed. This switching action is coordinated with the compressor’s internal overload protector and the run winding so the compressor receives sufficient inrush current only long enough to overcome static friction and refrigerant drag, minimizing heat buildup and preventing prolonged motor stall.
Compatibility decisions focus on terminal layout, inrush/current rating, and physical mounting so the relay matches the compressor’s electrical characteristics. Technicians typically check that the relay fits the compressor terminal pattern (commonly labeled C, S, and R), that its rated starting current meets or exceeds the compressor’s requirement, and that the relay cooperates with the overload protector used in the circuit. practical failure indicators include a humming compressor that will not start, intermittent starting, or tripped protection; bench checks include visual inspection, continuity/resistance checks between terminals, and substituting a confirmed-good relay to isolate the fault before replacing components to ensure proper system behavior.
- Common symptoms: compressor hums but does not run, repeated start attempts, or breaker trips.
- Quick tests: inspect for burn marks,measure continuity/resistance across start and run terminals,and perform a controlled substitution test with a known-good relay.
- Replacement checks: verify terminal arrangement, inrush/current rating, and physical mounting to match the compressor and overload device.
| Item | Description |
|---|---|
| Terminal labels | C (Common),S (Start),R (Run) – must match compressor terminals for correct connection |
| Typical environment | Residential refrigerator systems (line-voltage mains); confirm voltage and current ratings on the relay specification before replacement |
| Failure indicators | Humming/no-start,increased start attempts,or tripped circuit protection; often resolved by relay replacement after verification |
Common Failure Modes and Diagnostic Symptoms of the Start Relay
The 297237702 Frigidaire Refrigerator Start Relay is an electromechanical/electronic device that momentarily applies the compressor start winding to produce the torque required to turn a hermetic compressor from rest. In normal operation the relay provides a high inrush path to the start winding and then removes it once the compressor reaches running speed, often including a built‑in thermal protector or PTC element to prevent extended start current. Compatibility requires that the relay match the compressor’s start/run terminal layout and electrical characteristics; replacing this part with a visually similar relay can still fail if coil resistance, trip temperature, or terminal arrangement do not match the compressor specification and cabinet harness mounting.
Common failure modes include open circuits,welded or stuck contacts,degraded PTC elements or thermal protectors,and heat‑related degradation of plastic housings or terminals. These faults produce repeatable diagnostic symptoms: rapid or rhythmic clicking as the relay attempts to engage, a humming compressor that never reaches speed, repeated short cycling, blown thermal protectors, or visible charring at relay terminals. For practical diagnosis, technicians typically check for continuity across relay terminals, intermittent contact under manual vibration, and evidence of overheating; a compressor that will start if given a manual spin strongly indicates the start circuit (relay/PTC) rather than the compressor motor itself.
- rapid clicking or click‑pause sequences during start attempts
- Compressor hums but does not run or runs intermittently
- Visible burning, melted housing, or discolored terminals
- Repeated tripped breakers or blown internal thermal protectors
| Item | Description |
|---|---|
| Open circuit | No continuity between start terminals; compressor will not start and relay shows infinite resistance |
| Stuck closed | Relay fails to drop out, causing sustained start winding current, overheating, and possible compressor damage |
| Intermittent contact | Intermittent continuity causes erratic starting, rapid clicking, and repeated cycling |
Troubleshooting procedures and Electrical Tests for Start Relay Diagnostics
the 297237702 frigidaire Refrigerator Start Relay is a centrifugal/PTC style device that momentarily engages the compressor’s start winding to provide initial torque; it does not act as a run capacitor but as a switch to connect the start circuit during spin-up. Failures typically present as a humming compressor that will not start, repeated clicking as overloads trip, or intermittent starts after warm-up. Visual evidence such as melted plastic, burn marks, or a burnt odor often indicates internal failure; mechanical noise or lose parts inside the relay can also degrade starting performance. Compatibility should be confirmed against the compressor model and OEM part cross-reference because relay characteristics (timing, contact configuration) must match the compressor’s start/run windings to prevent repeated stress or premature motor damage.
Troubleshooting begins with basic non-powered inspections and progresses to controlled electrical testing. Disconnect power to the appliance before removing the relay and overload protector assembly from the compressor; then perform a continuity check across the relay terminals with a digital multimeter-open circuits on expected closed terminals indicate failure. Check for short-to-ground between any terminal and the compressor casing and verify that the overload protector returns to closed when cool. For more definitive results, measure current draw with a clamp ammeter during start: excessive starting amps or no current during attempted starts point to a defective relay or weak start winding. If electrical measurements are ambiguous, bench-testing by substitution with a known-good relay (matching the 297237702 specifications) or replacing the relay and retesting the system is a practical confirmation step; always re-check wiring, connectors, and the overload device when diagnosing compressor start failures.
- Common symptoms: humming, clicking, failure to start, intermittent running
- Basic tests: visual inspection, continuity, insulation/ground test
- Advanced verification: clamp-ammeter start-current measurement, substitution with known-good relay
- Compatibility: confirm part cross-reference and terminal configuration for the compressor model
| item | Description |
|---|---|
| Continuity check | measure continuity between start/run terminals; open circuit on expected closed paths indicates relay failure |
| Short-to-ground | Verify no continuity from any relay terminal to compressor chassis to rule out internal shorts |
| Start current | use a clamp metre during startup; abnormally high or zero start current helps isolate relay vs. winding faults |
Q&A
What is the 297237702 Frigidaire refrigerator start relay?
The 297237702 is a replacement start relay/overload assembly sold for certain Frigidaire refrigerators. It mounts on the compressor and helps the compressor motor start by switching additional starting current to the motor for a brief period, then dropping out once the compressor is running.
What does a start relay do and why is it critically important?
The start relay provides a temporary boost to the compressor’s start winding so the compressor can overcome initial inertia and begin pumping refrigerant. Without a working start relay the compressor may fail to start, hum constantly, overheat, or repeatedly try to start and trip the overload or breaker, which leads to cooling loss.
What are common symptoms of a failing 297237702 start relay?
Typical symptoms include: the refrigerator not cooling, compressor humming but not running, frequent clicking, an overheated relay or burnt smell, fridge cooling intermittently, or the compressor starts for a short time then stops. Some relays also rattle or feel loose when shaken, which can indicate internal failure.
How can I test the start relay to know if it’s bad?
First unplug the refrigerator. Remove the relay from the compressor (or the relay/overload cover) and visually inspect for burn marks, melted plastic, or a broken connector. Basic tests include shaking it (excessive rattle suggests failure) and using a multimeter to check for continuity between relay terminals; an open circuit where there should be continuity is a fault. for more precise diagnosis, test the compressor windings (start-run, start-common, run-common resistances) per manufacturer specs or have a technician perform an amperage/start-capacitor test.If you’re not pleasant working around the compressor or electrical parts, call a qualified appliance technician.
Is the 297237702 relay compatible with my Frigidaire model?
Compatibility depends on the refrigerator model and compressor type. Always check your fridge’s model number (on the label inside the cabinet or on the back) and cross-reference it with the part listing or Frigidaire parts database. Many online retailers and official parts pages let you enter your appliance model to confirm compatibility. If in doubt, contact Frigidaire support or an appliance parts supplier with your model number.
Can I replace the start relay myself? What are the basic steps and safety precautions?
Yes, a competent DIYer can often replace it, but observe safety: unplug the refrigerator first and wait a few minutes. Access the relay by removing the compressor access cover (usually at the back or bottom). Carefully pull the old relay off the compressor terminals and note orientation, then push the new relay on snugly. Reinstall the cover and restore power. Do not attempt to bypass the relay or connect things in ways not intended – that can damage the compressor and create fire risk. If the compressor or sealed system needs service,call a licensed technician; refrigerant work requires certification.
How much does a 297237702 start relay cost and where can I buy it?
Price varies by seller but start relays/replacement kits typically range from about $10 to $60 depending on whether it’s OEM or aftermarket and if it includes an overload. Purchase from Frigidaire/Electrolux parts dealers, appliance parts stores, or reputable online retailers. Buying OEM (genuine Frigidaire) parts reduces compatibility risk.
If replacing the relay doesn’t fix the problem, what else should I check?
If a new relay doesn’t solve the issue, possible causes include a failed start capacitor (if present), a faulty compressor, a bad overload protector, wiring or control board issues, or a sealed-system problem (low refrigerant or internal mechanical failure). A compressor that fails to run after a confirmed-good relay often requires professional diagnosis and repair, and sealed-system repairs must be handled by certified technicians.
Concluding Remarks
The 297237702 Frigidaire refrigerator start relay plays a critical role in initiating compressor operation and maintaining reliable cooling performance. As the component that helps the compressor start and run efficiently, a properly functioning start relay contributes to consistent temperature control, energy efficiency, and the long-term health of the refrigeration system.
As symptoms of a failing start relay can resemble other electrical or mechanical issues, accurate diagnosis and timely replacement with the correct part are critically important to prevent food loss and avoid further damage to the refrigerator. Engaging a qualified technician or following manufacturer-recommended procedures ensures safe testing and installation, protects warranty coverage where applicable, and helps restore dependable operation with minimal disruption.
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