AEC NEC Central Station Air and Water Cooled Chiller - Manual (Page 33)

Page 32 NEC Series Water- and Air-Cooled Central Chillers
4-7 Oil Pressure Safety Switch
This differential pressure switch monitors the pressure difference between crankcase pressure
and oil pump pressure. If pressure should drop to an unsafe level for more than two minutes, the
switch will open the control circuit.
Note: The oil pressure safety switch is a manual reset control. Call a refrigeration service
technician to analyze the problem and to reset the control.
4-8 Flow Switch
This switch shuts down the chiller if the evaporator water flow falls below a safe operating
gallon-per-minute rate.
4-9 Remote Start/Stop Interlock
Figures 16 and 17
A dry contact may be wired to allow the remote start or stop of an NEC chiller.
To use this feature, remove the jumper between terminals 4 and 4A on TB2. Supply a switch or
dry contact interlock connected in series between these two terminals.