157
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Discontinued
Part of the Setpoint Controls Series
Ordering Code: 157
UPC: 779655015701
Difference Setpoint Control, Variable Speed
The Difference Setpoint Control 157 is designed to use a variable speed pump to transfer heat from an intermittent heat source to a storage tank. It can be used in many different solar applications, including closed systems, drainback, or heat dump installations. Two sensors are used to measure the temperature at the source and at the storage location, and begin heat transfer when there is a positive difference between them. This product uses variable speed technology to operate a permanent capacitor wet rotor circulator to vary the rate at which heat transfer occurs.
Features
- Drainback capability, heat dump operation
- Heat supplement mode
- External heat exchanger mode
- 120 V (ac) powered pump outputs
- Second on/off pump
- Optional auxiliary sensor input to be used in heat dump and heat supplement modes
- Freeze protection
- Displays and logs total amount of energy transfer in BTU or kWh
- Certified to CSA and UL standards for use in the USA and Canada
| Specifications | |
|---|---|
| Agency Approvals | CSA C US, meets class B: ICES & FCC Part 15 |
| Ambient Conditions | Indoor use only, 32 to 104 degrees F (0 to 40 degrees C), RH less than or equal to 90 percent Non-condensing |
| Control Type | Microprocessor control, this is not a safety (limit) control |
| Demand | 24 V (ac) 2 VA |
| Dimensions | 4 3/4 IN H x 2 7/8 IN W x 7/8 IN D (120 x 74 x 22 MM) |
| Enclosure Material | White PVC plastic |
| Enclosure NEMA Rating | NEMA 1 |
| Hydronic - HVAC Control Type | Difference Setpoint Control |
| Power Supply | 24 V (ac) plus / minus 10 percent, 50/60 Hz, 3 VA |
| Pump Power | Pump 2, 120 V (ac) 5 A, 1/6 hp |
| Relay | No Relay |
| Sensor | NTC thermistor, 10 k ohms at 77 degrees F (25 degrees C plus / minus 0.2 degrees C) Beta=3892 |
| Variable Pump | 120 V (ac) 2.4 A (FLA), 5 A (LRA), 1/6 hp |