Applicable Systems
RTAC 200
Symptoms
The Trane RTAC chiller displays alarm E02, indicating high discharge pressure. The refrigerant discharge pressure has exceeded the safety limit.
Possible Causes
- Condenser coils dirty or fouled reducing heat rejection
- Condenser fan motors not operating or running in wrong direction
- Refrigerant overcharged causing excessive system pressure
- High ambient temperature reducing condenser capacity
Troubleshooting Steps
- Step 1: Clean condenser coils and verify airflow is unobstructed
Coils should be free of dirt, debris, and obstructions; use coil cleaner if necessary - Step 2: Check all condenser fan motors are running
Each fan should start and run at full speed; check fuses and contactors for failed fans - Step 3: Verify refrigerant charge level against nameplate data
Overcharge increases discharge pressure; recover excess refrigerant if overcharged - Step 4: Check ambient temperature at condenser intake
If ambient exceeds design conditions, consider additional ventilation or shading
How to Reset
To reset: 1) Clean condenser and verify fan operation. 2) Press reset on the control panel. 3) Monitor discharge pressure during operation. Caution: Repeated high discharge pressure alarms can activate the safety relief valve and cause refrigerant loss.
Frequently Asked Questions
- Q: What discharge pressure triggers E02?
E02 triggers when the discharge pressure exceeds the high-pressure safety switch setting, typically around 425 PSIG for R-134a systems. Refer to the specific model manual for exact thresholds.
- Q: Can I reduce the high-pressure limit setting to prevent E02?
No. The high-pressure safety limit is factory-set and must not be adjusted. The root cause of high discharge pressure must be addressed.
Source: Trane RTAC Chiller Troubleshooting Manual, Alarm Code E02
Category: Chiller