Troubleshooting - Bosch Greensource CDi TW Series Installation, Operation And Maintenance Manual

Greensource CDi Series TW Model

TROUBLESHOOTING

A possible fault may be one or a combination of causes and solutions. Check each cause and verify each
before making any conclusion.
Problem
ENTIRE UNIT DOES
NOT RUN
UNIT OFF DUE TO
HIGH-PRESSURE
CONTROL
UNIT OFF TO
LOW-PRESSURE
CONTROL
UNIT SHORT
CYCLES
Greensource CDi Series TW Model
Unit Troubleshooting
Possible Cause
Power Supply Off
Blown Fuse/Tripped
Breaker
Voltage Supply Low
Discharge Pressure is Too
High
Refrigerant Charge
High-Pressure Switch
High-Pressure Fault
Suction Pressure
Too Low
Refrigerant Charge
Low-Pressure Switch
Low-Pressure Fault
Unit Oversized
Thermostat
Wiring and Controls
Subject to change without prior notice
Checks and Corrections
Close disconnect, apply power
Replace fuse or rest circuit breaker. If using fuses, ensure
they are the correct size.
If voltage is below minimum voltage specified on unit data
plate, contact local power company.
If in "COOLING" mode: Lack of or inadequate water flow.
Entering water temperature is too warm. Scaled or
plugged condenser.
If in "HEATING" mode: Lack of or inadequate load side
fluid flow.
The unit is overcharged with refrigerant. Reclaim
refrigerant, evacuate and recharge with factory
recommended charge.
Check for a defective or improperly calibrated high-
pressure switch.
If the unit has UMC and a 40° F freeze sensor is being
used, this sensor is in series with HP switch and this will
show as a HP fault and not a freeze fault.
If in "COOLING" mode: Lack of or inadequate Source side
fluid. flow. Entering water temperature is too cold.
If in "HEATING" mode: Lack of or inadequate water flow.
Entering water temperature is too cold. Scaled or plugged
condenser.
The unit is low on refrigerant. Check for refrigerant leak,
repair, evacuate and recharge with factory recommended
charge.
Check for defective or improperly calibrated low-pressure
switch.
If the unit has UMC and the DPS option is being used, this
sensor is in series with LP switch and this will show as a
LP fault and not a DPS fault.
Recalculate heating and or cooling loads.
If the thermostat is installed near a supply air grill,
relocate thermostat. Adjust the heat anticipator.
Check for defective or improperly calibrated low-pressure
switch.
Troubleshooting | 31
8733954853 (2020/04)