AERCO Modulex EXT 321 - 1123 - Manual (Page 54)

MODULEX EXT 321, 481, 641, 802, 962, 1123 BOILERS
Installation, Operation & Maintenance Manual
in both poles, in an easily accessible position in order to provide a means to remove power from
the unit during servicing.
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
engineer. 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.
Service Relay Requirement 3.24.3
Upstream of the electrical connection, a service relay is required (not supplied) which, when the
additional electrical safety devices 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.
Electrical Requirements 3.24.4
• 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.
• Verify proper operation after operation servicing.
NOTE
Verify proper operation of the boiler after all servicing operations.
Page 54 of 148 AERCO International, Inc. • 100 Oritani Dr. • Blauvelt, NY 10913 OMM-0087_0E
12/01/14 Phone: 800-526-0288 GF-143