Step - Honeywell AQ254 Series Manual

AQ250 SERIES HYDRONIC CONTROL PANELS
perature using LOAD reset, but not OUTDOOR
reset, as the AQ250 panel does not have input ter-
minals for an outdoor sensor.
In general, the top terminals of the AQ2000 Series
components carry low voltage (24 Vac) power and the
bottom terminals carry line voltage (120 Vac) power. This
is illustrated in Fig. 1. The two exceptions to this are:
1. AQ15740B Zoning Module for use with zone valves
with end switches.
2. AQ15540B Zoning Module when used with low volt-
age zone valves without end switches.
TRANSFORMER
LINE VOLTAGE
(120 V)
CONTACTS
SYMBOL
Fig. 2. Internal wiring for AQ2000 Series components line voltage relays.
68-0306—07
CONTROL MODULE
ZR
Fig. 1. AQ250 Control Panel layout (AQ25044B shown).
For these the two exceptions, the bottom terminals of the
Transformer and Control Module carry line voltage (120
Vac), but the bottom terminals of the Zoning Module will
carry low voltage (24 Vac) power.
The powered terminals on the bottom of the AQ2000
Series Control Modules and Zoning Modules are
connected internally, as shown in Fig. 2. The voltage
supplied to the N and L terminals is also available at the
adjacent terminal pairs when the hot ( ) relays are
switched.
Zone 1
Boiler DHW Aux
ZR Boiler DHW Aux
4
ZONING MODULE
Zone 2 Zone 3 Zone 4
M29032A
Zone 1 Zone 2 Zone 3
Zone 4
M29033A
LOW VOLTAG
(24 V)
LOW VOLTAG
(24 V)