Benchmark 750-3000 Boiler Operation, Service, Maintenance Guide - KOREA
SECTION 4 – MAINTENANCE
Page
54
of
144
AERCO International, Inc.
•
100 Oritani Dr.
•
Blauvelt, NY 10913
OMM-0128_0B
07/17/2017
Ph.: 800-526-0288
4.9.1 Low Water Cutoff (LWCO) - Capacitor Electrical Short Test
This test determines if there is an electrical short between the LWCO capacitor and the heat
exchanger. Perform the capacitor electrical short test as described below.
Low Water Cutoff – Capacitor Electrical Short Test Instructions
1.
Turn the AC power to the unit to OFF
.
WARNING!
High voltages are used to power these units and so it is required that power applied to
these units is removed first before performing the procedure described in this instruction.
Serious personal injury or death may occur if this warning is not observed.
2. Remove the Shell Harness Cable (male) connector from the P-5 (female) connector on
the rear panel of the C-More Controller (see Figure 4-10).
Figure 4-10: Removing Shell Harness Cable from P5 Conn. on C-More Rear Panel
3. Using an ohmmeter, connect one ohmmeter probe to the LWCO capacitor terminal on
the unit shell as shown on left in Figure 4-11.
4. Connect the second ohmmeter probe to Pin #6 of Shell Harness Connector (removed
from the C-More controller) as shown on right in Figure 4-11.
Figure 4-11: Connecting Ohmmeter between LWCO Probe & Shell Harness Cable
UNPLUG SHELL HARNESS CABLE
FROM P5 CONNECTOR
CONNECT 2
ND
LEAD
TO PIN #6
CONNECT 1
ST
LEAD
TO LWCO TERMINAL
OHMMETER
LWCO PROBE
ASSEMBLY CONNECTOR
19-PIN SHELL HARNESS
CABLE CONNECTOR