Service Relay Requirement; Electrical Requirements - Watts AERCO Modulex EXT Commercial Series User Manual

Modulex EXT Commercial Series Boilers User Manual
CHAPTER 4: Installation Instructions
WARNING!
DANGER OF FATAL ACCIDENT DUE TO ELECTRIC SHOCK! 120 VAC connections
may be present on the external connection board when power is supplied to the boiler.
The electrical connections must be carried out only by a qualified person. Before carrying
out the connections or any other operation on the electrical parts, always switch off and
disconnect the electricity supply and ensure for yourself that it cannot be accidentally
turned on.

4.24.3 Service Relay Requirement

Upstream of the electrical connection, a service relay is required (not supplied) which, when the
additional electrical safety devices (if any) intervene, shuts down the electrical supply to the on-
off fuel valve fitted on the gas supply circuit, but NOT to the boiler, so as to guarantee the
running of the pump and permit the boiler to cool down.

4.24.4 Electrical Requirements

•
No changes may be made to the wiring of the boiler.
•
All connections should be designed in accordance with the applicable regulations.
•
Label all wires prior to disconnection when servicing controls. Wiring errors can cause
improper and dangerous operation.
NOTE:
Verify proper operation of the boiler after all servicing operations.
OMM-0095_0H
GF-139
AERCO International, Inc. • 100 Oritani Dr. • Blauvelt, NY 10913
Phone: 800-526-0288
Page 49 of 144
09/15/2017