AEC ACOA Series Air-Cooled Central Chillers - Manual (Page 45)

6-18 Motor Overload Protection - 1TAS
Automatic Reset
This solid-state device monitors the internal temperature of the compressor motor. If the
maximum motor temperature is exceeded, the compressor will shut down. To reset the
1TAS
monitor, open the control switch for five (5) seconds.
6-19 Undervoltage Relay - UVR
Optional
This optional device protects the ACOA chiller from damaging undervoltage, phase reversal and
single phasing conditions. If the
UVR device trips, a control relay de-energizes and opens the
control circuit. An LED on the UVR device indicates a normal power supply.
6-20 Fan Speed Control - SCR
The fan speed control varies the speed of the fan, depending on head pressure. When discharge
pressure is 140 psig (965 kPa/9.65 bars) or below, the fan is at minimum speed. As discharge
pressure rises, the fan speed increases proportionally until it reaches full speed at 200 psig (1,379
kPa/13.79 bars).
Page 44
ACOA Series Air-Cooled Central Chillers