Water Cutoff (Lwco) Capacitor Integrity Test; Low Water Cutoff (Lwco) - Capacitor Electrical Short Test - Watts Aerco BENCHMARK 750 User Manual

Benchmark 750 – 1000 Boiler User Manual - INTERNATIONAL

7.9 WATER CUTOFF (LWCO) CAPACITOR INTEGRITY TEST

The LWCO capacitor should be tested for electrical shorts every 12 months and replaced,
then tested, every 24 months. The LWCO capacitor integrity test consists of two parts as
described in the next two sections. The first procedure explains how to test for electrical
shorting of the LWCO probe capacitor, while the second procedure instructs how to perform
the standard Low Water Cutoff test using the C-More controls.
Refer to Figure 7-8 for an illustration of the LWCO probe assembly and its typical installation.
Rear
Panel
Hot Water
Outlet Pipe
Figure 7-8: LWCO Probe Location (BMK750 Shown)

7.9.1 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.
1. Turn the AC power to the unit to OFF.
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.
OMM-0119_0A
GF-130-I
CHAPTER 7 – MAINTENANCE
LWCO Probe
Terminal
LWCO Capacitor Electrical Short Test
--WARNING! -
AERCO International, Inc. • 100 Oritani Dr. • Blauvelt, NY 10913
Ph.: 800-526-0288
LWCO Probe
Plastic Acorn Nut
Capacitor Assembly
(Covered By Large
Shrink Tubing)
Connector
(to Shell Harness)
Page 95 of 170
11/03/2016