ECR International CHB Application Manual page 54

CHB BOILER - DHW RESISTOR HARNESS KIT
Multi-Zone Pump System with DHW Tank
Thermostat and Isolation Relay
If DHW tank thermostat is applied to multi-zoned pump
application secondary pump operation is controlled by Argo
priority switch position.
NOTICE
Important:
• Before connecting to Key72 terminals, remove
jumper on terminal block.
• Before connecting Low Water Cut-off remove
jumper on terminal block. (Key 370)
1. Boiler thermostat contacts (KEY 72) are wired to
Argo ARM Zone Pump Control terminals (x-x). Zone
thermostats and zone pumps are also wired to Argo
Controller as shown on wiring diagram. See figure 2.
2.
Important - Remove factory installed resistors,
Terminal 7 and 8 on terminal strip (KEY 155).
3.
Attach resistor kit wire harness to terminal strip (White
wire to #7 / Red wire to #8). See figures 2 and 3.
NOTICE
Failure to observe wire coding will result in improper
boiler operation. See wiring diagram figure 2.
4.
Attach isolation relay provided to Argo Zone Control
using an electrical knockout. Secure using conduit nut.
See figure 1.
5. Extend brown and blue wires of wire harness to
normally closed (N.C.) contacts on isolation relay (blue
and yellow wires). Secure unused wire end of relay
contact (ORG-N.O.) using provided wire nut.
6.
Attach isolation relay coil wiring (24 VAC) to Argo
Controller. Connect White/Blue wire to Argo zone 1
(Tw) and white/yellow wire to Argo "Common". see
figure 2. Secure unused wire end of relay coil, 120V-
white/black using wire nut provided.
7.
Wire DHW mechanical tank thermostat to Priority Zone
(Tw/Tr) contacts on Argo Zone Control.
8. Important: Set Argo Priority Switch to:
a. ON position - CH pumps WILL shutoff during DHW
priority.
b. Do not operate this system with the Argo Priority
Switch in OFF position.
NOTICE
If Indirect Tank pump is used connect to Priority
Zone terminals (L1/N1) on Argo Controller.
9.
Restore gas service and electrical power.
Follow lighting and operating instructions.
Restart boiler.
Verify proper operation by following START UP
Procedure found in boiler's Installation, Operation and
Maintenance Manual.
FIGURE 1 - Isolation Relay
54
PN 240011270 REV B [03/11/2016]