Page 52 IM 781-2
Table 12. Hardwired Chiller’s Hardware Transformer Usage
Hardware Maximum VA Description
Remote I/O Module
10 Always required for hardwired chiller.
Evaporator Water Flow Switch Relay
2 (typical)* Always required for hardwired chiller.
Condenser Water Flow Switch Relay
2 (typical)* Required for water cooled chiller.
0-10 VDC to 4-20 mA Converter for
Chilled Water Temperature Reset
2.5 Required if chilled water temperature setpoint reset is desired for the controlled
chiller and the chiller can not accept a 0-10 VDC signal.
0-10 VDC to 4-20 mA Converter for
Capacity Limiting
2.5 Required if capacity limiting is desired for the controlled chiller and the chiller can
not accept a 0-10 VDC signal.
24 VDC Power Supply for Measuring
Amps with a Current Transducer
15 Required if chiller does not output % RLA directly.
Current Transducer
0 Required if chiller does not output % RLA directly.
*Verify VA of relay used.
If a remote I/O module is used, its transformer provides 40 VA, which means that one panel is required per hardwired
chiller. Figure 33 displays a typical wiring diagram if all additional hardware items are required.