Table of Contents
Advertisement
Internet Version for Reference Only
Page 28
Figure 38. Testing the manual reset hi-limit switch.
5.2.3 Testing the Electrical Power Supply
The electrical components operate with supply
voltage ranging from 103 to 126VAC at 60 Hertz (Hz).
To test the electrical power supply:
1.
Measure the voltage at the hot and neutral
connections inside the heater electrical junction
box.
2.
Voltage outside of the required range may be due
to poor wiring connections, to other loads (e.g.,
air conditioners, compressors) on the circuit,
to high pump load, or to an electrical utility
company problem.
5.2.4 Testing the Manual Reset
Hi-Limit Switch
To test the manual reset hi-limit switch (see
Figure 38):
1.
Touch the other lead of the voltmeter to both
terminals of the manual reset hi-limit switch.
The voltmeter should read 24 to 28VAC at both
terminals.
2.
If no voltage is detected at one terminal, reset the
manual reset hi-limit switch by pressing the reset
button. Check the temperature setting.
3.
If after pressing the reset button there is still no
voltage indicated at one terminal, replace the
manual reset hi-limit switch. An open switch
may indicate excessive water temperatures or
improper setting.
5.2.5 Testing the Flow Switch
The flow switch is a safety device that senses
water flow through the heater. When the switch senses
adequate water flow, it closes, allowing the heater to
fire. If the water flow is too low, the switch remains
open and prevents the heater from firing regardless of
the temperature control setting.
The flow switch is factory mounted and wired.
Never attempt to repair the flow switch. If the flow
switch is found to be defective, replace the flow
switch. To test the flow switch:
1.
Remove cap from flow switch.
2.
Touch a voltmeter lead to each terminal of the
flow switch.
3.
If the voltmeter reads voltage at each of the
terminals, the switch is good.
4.
If there is no voltage at one terminal, it indicates
an open switch. Check flow switch paddles to
determine if they are broken, missing or frozen.
Replace the flow switch.
5.2.6 Testing the Fusible Link
(flame roll-out switch)
The fusible link is a thermally fusible element
which shuts down the heater if it detects excessive
temperatures inside the heater flue collector
compartment. To test the fusible link (flame roll-out
switch, if installed):
1.
Touch the voltmeter lead to the lower terminal on
the terminal block (see Figure 39).
Figure 39. Testing the fusible link.
BRADFORD WHITE
Advertisement
Table of Contents
