Installation Preparation - Honeywell AQ25A Series Technical Reference Booklet

1 INSTALLATION PREPARATION

When Installing this Product...
1. Read these instructions carefully. Failure to follow
them could damage the product or cause a
hazardous condition.
2. Check the ratings given in the instructions and on
the product to make sure the product is suitable for
the application.
3. Installers must be trained, experienced, and licensed
service technicians.
4. Follow local codes for installation and application.
5. After installation is complete, check out the product
operation as printed in these instructions.
WARNING
Risk of electrical shock.
Can cause severe injury, property damage or death.
Disconnect power supply before installation and before
servicing.
Check That You Have All the Necessary
Equipment For a Successful Installation
• AQ2000 Series components:
— AQ2000 boiler Control Panel (such as AQ250, AQ25A,
AQ251, or AQ252)
— AQ254 "Add-A-Temperature" Expansion Control Panel
— AQ Expansion Zoning Panel (at least one Expansion
Zoning Panel must be connected to an AQ254 to pro-
vide input from zone thermostats associated with the
mixed temperature loop controlled by the AQ254)
— Digital thermostats (one for every space heating zone
being controlled)
• Secondary loop supply temperature sensor (included with
the AQ254 control panel)
• Mixing device (injection pump, floating 2-, 3- or 4-way
motorized mixing valve, modulating 0-10 Vdc [or 2-10 Vdc]
motorized mixing valve or variable speed pump
• Secondary loop pump
• Low voltage thermostat wire
• Zoning equipment (zone valves or pumps)
The AQ254 is designed to be connected to an AQ2000 boiler
Control Panel - it cannot be operated as a standalone device.
The AQ254 Control Panel can control a maximum of 16 zones
by connecting additional Expansion Zoning Panels to the
AQ254 Control Panel. The hydronic system can be expanded
by 16 zones for each AQ254 connected to the AQ2000
network. A maximum of three (3) AQ254 Panels may be
connected to an existing AQ2000 Control Panel for a
maximum of 64 zones connected on the AQUATROL®
network.
Read All Instructions Carefully Before
Proceeding
The AQ254 Control Panel is a part of a totally new family of
hydronic controls. And although they - and other AQ2000
system components - are very easy to install and operate, they
are different than other hydronic controls that you have
previously installed. So take a moment to read through this
AQ25400B "ADD-A-TEMPERATURE" EXPANSION CONTROL PANEL
Product Data sheet before beginning the installation. Failure to
follow them could damage the product or cause a hazardous
condition.
Familiarize Yourself With the AQ254 Control
Panel Layout
The AQ254 "Add-A-Temperature" Expansion Control Panel
consists of two functional components (see Fig. 1 on page 3):
• The AQ10X38 transformer (power supply module), which
connects to 120 Vac power and supplies 24 Vac power to
the Expansion Control Module and any connected Zoning
Modules.
• The Mixing Control Module, AQ15400B, which controls the
mixing device (pump or valve) to maintain the secondary
loop temperature according to the method of reset (outdoor
or load adaptive reset).
TRANSFORMER
LOW
VOLTAGE
(24V)
CONTACTS
SYMBOL
LINE
VOLTAGE
(120V)
Fig. 1. AQ254 Expansion Control Panel layout.
The top terminals of the AQ254 carry low voltage (24 Vac)
power and the bottom terminals carry line voltage (120 Vac)
power. This is illustrated in Fig. 1.
The powered terminals on the bottom of the AQ254 are
connected internally, as shown in by the dashed lines in Fig. 1.
The voltage supplied to the N and L terminals is also available
at the SEC pump and variable speed injection pump terminal
pairs when the hot ( ) relays are switched.
The 38 VA transformer included with the AQ254 has sufficient
capacity to provide low voltage power to the AQ15400B
Control Module as well as up to 16, AQ1000 thermostats.
All low voltage contacts (terminals 3 to14) on the top of the
AQ15400B Control Module are internally-powered.
IMPORTANT
Voltage must not be applied to the low voltage termi-
nals or the internal electronics of the AQ15400B could
be damaged.
The 10kΩ sensor for measuring the secondary loop (mixed)
temperature is the only low voltage input on the AQ254 Control
Panel (besides the 24 Vac R and C supply terminals). There
are two low voltage outputs: a 0-10Vdc (or 2-10Vdc)
3
CONTROL MODULE
M27808A
69-1987—02