Chiller Controller
SZ2166Description
The SZ2166 is a microprocessor-based chiller controller for use on multi-stage chiller applications. It includes boiler support and control functions.
Inputs:
- Six 1000Ω PtRTD, momentary override
- Five digital (dry contact)
- Chilled water supply and return: 0 to 100°F
- Hot water supply and return: 40 to 240°F
- Mixed water: 20 to 220°F
- Outdoor air: –40 to 160°F
Outputs:
- Nine digital (SPST dry contact, 24 VAC @2A)
- Two 4 – 20 mA DC analog
Maximum load resistance (analog output):
600Ω
Common mode rejection:
100 db @60Hz
Features
- Stand-alone or network operation
- 365-day time clock with two holiday schedules, automatic leap year and daylight savings correction
- Hot water supply-and-return temperature inputs
- Boiler support
- Separate setpoint for thermal storage sequence
- Outdoor air reset control
- Two digital inputs for pump status
- Lead/Lag sequencing of up to six chillers
- Two modulating analog outputs for valves and VFDs
- Adjustable P+I+D control on modulating outputs
- Automatic rotation of pumps
- Automatic rotation of chiller and boiler stages
- Pump lube feature
- Local and remote override capability
Specs & Docs
Specifications:
General
Accuracy: +/- 0.5%
Programming: EIA RS485 interface
Communications: RS485, half duplex
Memory backup: Non-volatile EEPROM, no battery required
Environmental
Operating temperature: 32 to 131°F (0 to 55°C)
Operating humidity: 0 to 100% RH, noncondensing
Storage temperature: 14 to 140°F (-10 to 60°C)
Electrical
Supply voltage: 24 VAC +/-20%
Inputs: Six 1000 Ω PtRTD, momentary override and five digital (dry contact)
Range: Chilled water supply and return: 0 to 100°F
Hot water supply and return: 40 to 240°F
Mixed water: 20 to 220°F
Outdoor air: -40 to 160°F
Outputs: Nine digital (SPST dry contact, 24 VAC @ 2A) and two 4 to 20 mA DC analog
Max. load resistance (analog output): 600 Ω
Common mode rejection: 100 db @ 60 Hz
Power consumption: 15 VA max.
Specifications subject to change without notice.
