AM Series Cascade Sequencer User Manual
OMM-0101_0D AERCO International, Inc. •100 Oritani Dr. •Blauvelt, NY 10913 Page 5of 28
GF-146-CS Ph.: 800-526-0288 04/29/2016
1.2 Electrical Installation
Access the electrical junction box as shown in Figure 1-2. Two wiring schematics (Figures 13a
and 13b) are shown on the following pages that show wiring for earlier and later manufactured
units. Determine which unit you have according to the two following conditions (a or b), then
wire according to the referenced figure number:
a) If terminals 30 and 31 are NOT present in the electrical junction box, refer to Figure 1-3a.
b) If terminals 30 and 31 ARE present in the electrical junction box, refer to Figure 1-3b.
Installer must install all wires represented by dashed lines in Figures 1-3a and 1-3b. The
“Cascade general sensor” is present inside each heater’s accessory box. This sensor must be
electrically wired to terminals 24 and 25 of the Master heater # 1 and placed into the low loss
header of the cascade (see Figure 1-1).
The "daisy chain" wiring used to connect boilers should be shielded type and has a
maximum length of 300 ft. Unshielded wire is acceptable but not recommended, and the
maximum length is only 60 ft.
Depending on the control method of your system, additional wiring may be required.
For
outdoor reset using the included outdoor temperature sensor, connect the outdoor
temperature sensor to terminals 14 & 15 of the Master boiler. For remote setpoint
(0-10V)
control, connect the 0-10V signal wires to terminals 22 & 23 of the master boiler.
For Modbus
control of the operating setpoint connect to terminals 18, 19, and 20. For
further information
on Modbus, see GF-146-MB.
If there is a water heater tank present in the system, the tank
sensor should be placed in the
bottom 1/3 of the tank. This sensor is included in the spare parts kit shipped with each unit,
and is the same probe as the cascade header temperature sensor.
If using the AM for domestic hot water only, connect the sensor leads to terminals 24 and 25.
For further information on all of these control modes, consult the AM Series Boiler and
Water Heater User Manual (GF-146).
Figure 1-2: Accessing the Junction Box of the Master Heater
Communications
Board Cover
Junction Box
Top Cover
Top Cover Screw
