Specifications
WARM-UP KIT
FIGURE 35
J
8
P
8
Page 30
Optional filter switch kit is required to make the
filter light functional.
J-Commercial Controls Hardware
All GCS24 units are factory equipped with the hardware
required to connect and operate Lennox' Commercial
Controls (W973, W7400, economizer, warm-up, etc...).
The hardware consists of an economizer wiring harness, a
control system wiring harness and associated jackplugs.
The economizer and control harnesses are pre-wired to
facilitate economizer, controls and/or warm-up connec
tions.
Each unit is equipped with marked jackplugs at various
locations throughout the unit. Each jack is marked with a J"
number on the jack (for example J5) and a corresponding
P" number on the plug (for example P5). The J16/P16 jack
plug and the J3/P3 jackplug are used as connection points
for commercial control systems in all Lennox commercial
equipment. Lennox supplied control systems are prewired
with plugs which match the corresponding jackplugs in the
unit.
Following is a list of important jackplugs found in Lennox 10
and 12.5 ton commercial equipment and the function of each:
1 - Jack J3 / Plug P3
Jack J3 is located in the unit filter section of all units. It is
wired to the unit wiring harness and is used for the con
nection of an economizer or any of the relay kits which
are used to interface optional controls to the unit.
The mating plug P3 is a jumper plug which is necessary
to complete circuits internal to the unit when the unit is
operated without accessories. When the unit is operated
with accessories, P3 is removed and discarded.
2 - Jack J16 / Plug P16
Jackplug J16/P16 is located in the unit control box .
Jackplug J16/P16 is used exclusively as a connection
point for the control portion of optional control systems.
Plug P16 is wired to the unit low voltage terminal strip
and jack J16 is wired to the unit wiring harness.
3 - Jack J35 / Plug P35
Jackplug J35/P35 located in the unit control box is used
for assembly line tests only. J35/P35 is not used for the
connection of any control or control system.
K-Optional Commercial Controls Systems
Optional 24 Series Commercial Controls" may be connected
to both the 10 and 12.5 GCS24 units. These are the same
controls which are optional in all 24 series commercial units.
The following list describes the components used in all cur
rently available (at time of printing) optional control system
combinations. Each system is assigned a C" number for
easy reference. The C" number identifies the control system
on the wiring diagram (likewise, each GCS24 unit wiring dia
gram is assigned a B" number, each heating section is as
signed an A" number and each economizer diagram is as
signed a D" number). Look for these numbers on the dia
gram to help you identify how the unit is set up and which con
trol system is being used.
The control system wiring diagrams and the accompanying
system Operation Sequences" are not included in this manu
al.
The following section is provided to help service personnel
become familiar with Lennox' Commercial Controls and the
associated wiring schemes.
1 - D5 Wiring Diagram - Modulating Economizer
Model Number REMD24M-160
Downflow Modulating Economizer. Optional field
installed in all GCS24 units. Sensors continuously moni
tor air conditions and adjust dampers accordingly. Mod
ulating economizer provides an infinite number of damp
er positions.
All wiring connections are made by jackplug connec
tions to the commercial controls harness in the unit.
Plug P4 in the economizer connects to Jack J3 in the
unit to make this connection.
2 - Warm-Up Kit
Warm-up kit is shown in Figure 35 . Warm-up kit is an
accessory to the economizer (diagram D5).
The kit provides warm-up capabilities by holding outdoor
air dampers closed
during the first heating
period after night set
back. When first heat
ing demand is satis
fied, warm-up kit al
lows outdoor air
dampers to open to
minimum position.
Warm-up kit does not have its own wiring diagram. It is
included in the C2, C4, C6 and C14 wiring diagrams.