44
PHTM II
Combi Installation, Operating & Service Instructions
110331-07 - 8/23
13
Field Wiring
(continued)
From left to right, connections on terminal strip
are:
Terminal
Description
120 VAC L
Hot
120 VAC N
Neutral
Boiler Pump L
Not used on Combi
Boiler Pump N
Not used on Combi
System Pump L
Hot
System Pump N
Neutral
Auxiliary Pump L
Hot
Auxiliary Pump N
Neutral
3. Pump outputs
A. System Pump: (field supplied) Circulates
water through radiation. System pump
is always on when boiler is responding
to heating demand. Refer to Table 16-15
for alternate system pump output functions.
Maximum recommended current draw for
system pump is 1.5A.
B. Auxiliary Pump: ("Recirculation pump")
(field supplied) Circulates water through a
DHW recirculation loop. Auxiliary pump output
can be used for 2nd zone or indirect pump.
Refer to Table 16-15 for more information
and alternate auxiliary pump output
functions. Maximum recommended current
draw for auxiliary pump is 1.5A.
C. Maximum combined current draw for all
circulators is 5A. Internal boiler pump
draws a maximum of 2A.
From left to right, connections on terminal strip
are:
Terminal
Description
Heat T'Stat 24 VAC thermostat (R - 24V "Hot")
Heat T'Stat 24 VAC thermostat
(W - Energized on Call for Heat)
Heat T'Stat 24 VAC thermostat (C - 24V Common)
Aux T'Stat
24 VAC thermostat (R - 24V "Hot")
Aux T'Stat
24 VAC thermostat
(W - Energized on Call for Heat)
External
Limit
Field supplied safety limit contacts (1)
External
Limit
Field supplied safety limit contacts (2)
0-10 V
4-20mA
Optional remote modulation control* (+)
0-10 V
4-20mA
Optional remote modulation control* (-)
Header
Sensor
Optional Recirculation (Header*) Temperature
Sensor (1)
Header
Sensor
Optional Recirculation (Header*) Temperature
Sensor (2)
Outdoor
Sensor
Optional Outdoor Temperature Sensor (1)
Outdoor
Sensor
Optional Outdoor Temperature Sensor (2)
*Feature available with PAT-Connect Bluetooth
Adaptor and App.
Figure 13-2: 120 VAC Connections
120V
Line
Boiler
Pump
Aux
Pump
GND
L
N
L
N
L
N
L
N
System
Pump
L2
Power Supply
120/60/1
Overcurrent Protection/ Disconnect
Service Switch
L1
Low Voltage Connections
Figure 13-3: Low Voltage Connections
1. All low voltage field connections to boiler are
made on Low Voltage Connections terminal strip
(see Figure 13-3) located on left side of bottom
panel. Route all low voltage wiring through
conduit knock out holes located on left side in
front of terminal strip.