Boiler Controller
SZ2165Description
The SZ2165 is a microprocessor-based boiler controller for use in multi-stage boiler applications. It includes chiller support and control functions.
Inputs:
- Six 1000 Ω PtRTD, momentary override
- Five digital (dry contact)
- One 4 to 20 mA DC analog
- Hot water supply and return: 40 to 240°F
- Chilled water supply and return: 0 to 100°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
- Hot water supply-and-return temperature inputs
- Chiller support
- Two digital inputs for pump status
- Local override and remote override capability
- Digital outputs for boilers, pumps, and boiler stages with adjustable offsets and differentials
- Lead/Lag sequencing of up to four boilers
- Analog input for pressure control
- Two modulating analog outputs for valves and VFDs
- Adjustable P+I+D control on modulating outputs
- Automatic rotation of pumps
- Automatic rotation of boiler and chiller stages
- Domestic hot water function
- Pump lube feature
- Selectable normally open or normally closed relay outputs
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, non-condensing
Storage temperature: 14 to 140°F (-10 to 60°C)
Electrical
Supply voltage: 24 VAC +/-20%
Inputs: Six 1000 Ω PtRTD, momentary override, five digital (dry contact) and one 4 to 20 mA DC analog
Range: Hot water supply and return: 40 to 240°F
Chilled water supply and return: 0 to 100°F
Mixed water: 20 to 220°F
Outdoor air: -40 to 160°F
Outputs: Nine digital (SPST dry contact, 24 VAC @2 A) and Two 4 to 20 mA DC analog
Analog input impedance: 250 Ω
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.
