Problem 57: Over/Under Voltage Diagnostic On Startup; Problem 58: Phase Loss - Trane CVHE Troubleshooting Manual

This is out of range and thus a sensor diagnostic is being called. The diagnostic
may be cleared once the chiller is charged.

Problem 57: Over/Under Voltage Diagnostic on Startup.

Overvoltage is a + 10% must hold and +15% must trip. Undervoltage is a must
hold –10% and must trip –15%.
Corrective Action:
1 Check main power supply and wiring.
2 You may get the diagnostic with the following Setup Sequence.
~ Unit Line Voltage enabled in Machine Configuration.
~ Under/Over Voltage is enabled in Field Startup.
~ If you then disable Unit Line Voltage, the Under/Over Voltage screen disappears but is still
active. You have to then re-enable Unit Line Voltage in Machine Configuration and disable
Over/Under Voltage.
3 Over/Under Voltage is used only with PTs installed. If you enable the option with "No" PTs
installed you will get the diagnostics.
4 When the Line Voltage Sensing Option is not installed, the Unit Line Voltage menu item is not
displayed nor is the Under/Over Voltage option installed.

Problem 58: Phase Loss

There are 2 variations of this diagnostic:
Less than 10% current was sensed on one or more of the current Transformer inputs.
Time to trip is 1 second minimum, 3 seconds maximum. This is a MMR diagnostic.
A second and less common method of receiving phase loss diagnostic is via the
phase reversal protection circuit of the Starter module. Phase rotation protection is
enabled and either the Phase A current signal or the Phase C current is less than 5%
of the CT rating, then phase loss will be called out. Time to trip is 0.7 seconds for
CTV during start.
Corrective Action:
1 CT hooked incorrectly relative to incoming power.
2 Defective Primary CT (See CT Checkout Procedure).
3 120 VAC missing from the Stop Relay circuit on J6 of Starter module.
4 Defective High Pressure switch. Wire may be off.
5 Problem in the Start Relay circuit on J8 of Starter module. Check all connections and circuit.
6 Verify currents are over 10% RLA.
7 Check the current overload settings.
8 Defective Starter module.
9 Turns through the CTs may be incorrect.
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