MC2: 10/03/12 Page
30
of
90
AERCO International, Inc.
•
100 Oritani Dr.
•
Blauvelt, NY 10913
•
Ph: 800-526-0288
GF-115-H
OMM-0083_0B
Modulex MLX Series Gas Fired Boiler System
Operation and Maintenance Manual
Chap 6:
Electrical
The Modulex boiler should be wired for power per the instructions and
Figure 6-1
below.
Wiring the MLX Boiler for Power
1. External power at 120 VAC, 60 Hz, single phase is first connected to the Low Water Cutoff and
Aquastat provided on the CSD-1 Supply Manifold. Refer to
Wiring Diagram 68004
provided in the
manual package for connections to the CSD-1 Manifold.
2. Following connection of 120 VAC power to the CSD-1 Manifold, the power leads are routed to the
Junction Box shown in
Figure 6-1
. The Junction Box is accessed by removing the front panel from
the boiler.
3. Route the wires from the CSD-1 Manifold through the cutout labeled 120V
on the Left side of the
boiler. If necessary, the cutout labeled 24V is used for low voltage signals such as external
sensors.
4. The boiler’s Junction Box contains a polarized terminal block. Therefore, the Red (Line - L1) and White
(Neutral - L2)
wires from the CSD-1 Manifold
MUST BE
connected to terminals L1 and L2
respectively on the terminal block in the Junction Box. The output cable from the Junction Box is
terminated with a 3-pole plug, which connects to the boiler’s electrical components. If incorrectly
wired, the boiler goes into a “lockout” condition.
It is necessary to install a double-pole switch on the supply line in an easily accessible position in order to
quickly and safely disconnect service.
DO NOT
affix switch to boiler sheet metal enclosure.
Figure 6-1: Junction Box Wiring
After placing boiler in operation, the ignition system safety shutoff device must be tested. If an external
electrical source is utilized, the boiler, when installed, must be electrically bonded to ground in
accordance with the requirements of the authority having jurisdiction or, in the absence of such
requirements, with the National Electrical code (NEC), ANSI/NFPA 70 and/or the Canadian Electrical
Code (CEC) Part I, CSA C22.1, Electrical Code.
Cable to
3-Pole
Plug
L2
Ground
L1
Terminal Block
3-Pole Plug
Cover
Terminal Block
