P-K Storm
TM
Gas Fired Boiler
Technical Service 1.877.728.5351
Revised: June 26, 2020
Released: June 26, 2020
©
Patterson-Kelley 2020
All Rights Reserved.
2691000273 P-K Storm ST2500-ST4000
Installation and Owners Manual Rev A.docx
Page 16
High Voltage (TB2) Terminal Block
Start Interlock #2
–
The Start Interlock #2 TB2-1 and TB2-2 terminals are in series with Start Interlock
#1 and provide additional connection points for auxiliary safety devices. This circuit is energized with
120VAC, so the contacts on any auxiliary safety devices must be rated for minimum 120VAC.
Start Interlock #1
–
The Start Interlock #1 TB2-3 & TB2-4 terminals can be used for auxiliary safety
devices such as damper limit switches, control valve limit switches, emergency stop buttons, and low
water cutoff devices. This circuit is energized with 120VAC, so the contacts on any auxiliary safety
devices must be rated for a minimum of 120VAC. The appliance ships with a factory-installed jumper
across Start Interlock #1 and Start Interlock #2 terminals. Remove the jumper(s) if using any auxiliary
safety devices.
Be sure to check the
nameplate on the boiler
before connecting the
electrical supply.
N
OTICE
!
A dedicated earth ground
(green wire) is required to
avoid nuisance shutdowns.
Do not ground through the
conduit!
The high voltage (TB2)
terminal block on the Storm
boilers with NURO controls
contains dry-contact relays
with a maximum voltage
rating of 240VAC and 1/2 Amp
maximum current capacity.
Incorrect wiring can result in
equipment damage, injury, or
death.
