Honeywell AQ25A Series Technical Reference Booklet page 78

AQ251 SERIES BOILER RESET CONTROL PANELS
Step 5 – Line Voltage System Outputs
Refer to Fig. 15 and follow the steps in this section to wire
these devices to the AQ251 Control Module.
"1. Boiler Pump"
"2. DHW Device"
"3. Line Voltage Rated Aux Output (Aux. pump)" on page 13
FROM LINE VOLTAGE 120V
TERMINALS (N AND L) ON
BOTTOM OF TRANSFORMER
TO BOILER
TO LINE VOLTAGE 120V
TERMINALS 17-18
TERMINALS (N AND L) ON
ON TOP OF AQ15100B
BOTTOM OF TRANSFORMER
CONTROL MODULE
L8148, L7148
T T
G L2 L1 C2 C1
L2
1
L1
(HOT)
BOILER
PUMP
1. Boiler Pump
Connect the N and L wires of the boiler loop pump to the N and
switched hot terminals of the line voltage Boiler output, shown
in Fig. 17 on page 13. The ground wire of the pump can be
connected to any of the 8 ground screw terminals located on
the back surface of the Control Panel enclosure.
The boiler pump contacts are made after any one of the
following occur:
• A call for heat has occurred from any heating zone.
• The Heat input is shorted on terminals 11 and 12.
• The DHW input is shorted and the DHW type is configured
as a valve.
The pump is delayed for the FIRE DELAY programmed in the
EQUIPMENT SETUP > BOILER OPERATION sub-menu (see
Fig. 25 on page 39). The boiler pump and the last zone calling
remain on in order to move heat out of the boiler for the period
of time programmed in the Purge time menu under the fire
delay. Manually adjusting thermostats affects the operation of
this software so it can not be tested manually, you must
observe it under normal operating conditions.
NOTE: If the AQ251 is connected to a modulating
condensing boiler, the boiler pump may need to be
connected to the boiler, not the AQ251. Confirm this
with the boiler's installation manual.
69-1974—04
N L
ZC
ZR
B2 B1
POWER SUPPLY. PROVIDE DISCONNECT MEANS AND OVERLOAD PROTECTION AS REQUIRED.
1
Fig. 15. Line Voltage Connections for AQ251.
TO AUXILIARY DEVICE
(INSTALLER-DEFINED)
R8184A, R7184
T
T
BLACK
2. DHW Device
Wire the DHW pump or line voltage zone valve to the N and
switched hot terminals of the DHW output, as shown in
Fig. 17 on page 13.
If using a low voltage zone valve, wire the primary of a spud-
mounted transformer (115V to 24V) to the DHW line voltage
contacts and connect the low voltage zone valve to the
secondary terminals of this transformer. A spud-mounted
transformer may be located in one of the conduit knockouts on
the bottom of the AQ251 Control Panel.
Alternatively, a 24 Vac zone valve can be connected to the
Aux. pump line voltage-rated dry contacts, which can be
configured to close on a DHW call. This configuration is
defined in the Installer Equipment Setup menu beginning on
page 30.
The DHW contacts are made when the DHW inputs on
terminals 13 and 14 are shorted by the controlling Aquastat.
This is a line voltage output designed to go to the DHW pump.
If 24 Vac is needed for a low voltage valve, you can mount a
step-down transformer on the conduit opening and wire the
valve from the transformer. When DHW is enabled, the system
has a 30-minute priority over all calls for heat. After 30 minutes,
calls for heat are added back in to the operation for 30 minutes
and then turned off again. This repeats until the DHW is
satisfied.
12
F
C554
F
ORANGE
BURNER AND
IGNITION
M27742A