Safety Controls; High Pressure Control (Hpc); Low Temperature Control (Ltc); Low Pressure Control (Lpc) - Cornelius CH1500 Operator's & Installation Manual

Each chiller is provided with three standard safety controls. There controls are arranged in series in the control circuit
to automatically shut down the unit in the event that a condition exists which could be harmful to the refrigeration
system components.

High Pressure Control (HPC)

This control prevents system operation in the event that the high side pressure exceeds 250 PSIG. If this occurs,
check the following:
1 That the condenser and condenser air filter are clean and that the air inlets and outlets are unobstructed.
2 That the ambient temperature at the chiller location is below 110
3 That the fan blade is rotating.
Press the reset button located on the front of the High Pressure Control to restart the chiller. This control is
mounted in the lower left hand corner of the electrical box. If the control opens again, check the control set-
ting with refrigeration gauges. If the setting is correct, contact the Technical Service Department.

Low Temperature Control (LTC)

This control prevents system operation in the event that the fluid inside the evaporator falls below 35
check the following:
1 That the thermostat set point is set at 40
2 That the flow through the system is greater than two gallons per minute.
This control is mounted in the lower left hand corner of the electrical box. It automatically resets itself once
the water temperature is restored to 38°F. The low temperature control may be adjusted for lower tempera-
tures if a glycol solution is used. Contact the Technical Service Department for temperatures below those
stated here. Also see Fluid Recommendations on page .

Low Pressure Control (LPC)

This control prevents system operation in the event that the low side pressure falls below 21 PSI. If this occurs, check
the following:
1 That the thermostat set point is set at 40
2 That the flow through the system is greater than two gallons per minute.
3 That no bubbles are present in the sight glass.
4 That the water bypass valve allows flow through the chiller in a "dead head" situation.
This control is located to the right of the high pressure control in the electrical box. It automatically resets
itself once the low side pressure rises to approximately 41 PSI. If the control opens again, check the con-
trol setting with refrigeration gauges. If setting is correct, contact the Technical Service Department.
© 2010-2014, Cornelius Inc.
CH1500, CH2000 & CH3000 Chiller Operator's & Installation Manual

SAFETY CONTROLS

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Publication Number: 621055837OPR
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