Terminal Block Assignments; Terminal Block Assignments - Low Voltage (Tb1) Terminal Block - Patterson-Kelley P-K STORM ST-1250 Installation & Owner's Manual

6.1 Terminal Block Assignments

Terminal Block Assignments — Low Voltage (TB1) Terminal Block
Terminal Number Label
ECOM 3
27
ECOM 2
26
ECOM 1
25
MODBUS SHIELD
24
MODBUS COM B
23
MODBUS COM A
22
MODBUS/CASCADE REF
21
CASCADE B TO B
20
CASCADE A TO A
19
CASCADE SHIELD
18
GROUND
17
ANALOG OUTPUT [-]
16
4-20mA ANALOG OUTPUT [+]
15
NIGHT SETBACK
14
NIGHT SETBACK
13
OUTDOOR TEMP SENSOR
12
OUTDOOR TEMP SENSOR
11
DHW STAT / SENSOR
10
DHW STAT / SENSOR
9
HDR TEMP SENSOR
8
HDR TEMP SENSOR
7
SPARE ANALOG INPUT
6
SPARE ANALOG INPUT
5
ANALOG INPUT [-]
4
4-20mA ANALOG INPUT [+]
3
ENABLE / DISABLE
2
ENABLE / DISABLE
1
Revised: October 2, 2019
Released: October 2, 2019
Description
Wireless Outdoor Air Receiver
2-Wire MODBUS RS485 & Shield Terminal
Reference Terminal (Application Dependent)
2-Wire Cascade & Shield Terminal
Ground Terminal for I/O Devices
4-20mA Analog Output Tracks Boiler Firing Rate
100% Firing Rate = 20mA, 1% Firing Rate = 4mA
Contact Closure Enables Night Setback Operation
Open Circuit Disables Night Setback Operation
Outdoor Air Temperature Sensor for ODA Reset
Configurable for 10kΩ or 12kΩ Sensor
DHW Enable Circuit Configurable for SPST Break-on-
rise Aquastat, or 10kΩ or 12kΩ Tank Sensor
Hydronic Supply Header Temperature Sensor
Configurable for 10kΩ or 12kΩ Sensor
Reserved for Future Use
4-20mA Analog Input
Configurable for Setpoint or Firing Rate Control
Contact Closure Enables Comfort Heat Operation
Open Circuit Disables Comfort Heat Operation
 Patterson-Kelley 2019
All Rights Reserved.
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P-K Storm Gas Fired Boiler
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2691000099 P-K Storm Installation and Owners
Manual.docx
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