520 Indoor / 520 Outdoor Service Manual
Ver. 1.00
78
CONFIDENTIAL
12-15. Relay selection for the pump control connection
The maximum current capacity of the 520 Indoor or 520 Outdoor pump control connection is 1 amp.
Before using any relay with the pump control, please check the specifications of that particular relay to
ensure that the current value through the coil will not exceed 1 amp.
For example:
To the right, there is a sample of relay
specifications from an arbitrary brochure. You
can select either the 120 VAC or 240 VAC relay,
because their current values are less than 1 A
(1,000mA).
Power supply for relay
Normally 120 VAC
Through this circuit, the maximum
current capacity is 1 A
Connect to this “pump” terminal
Re
ci
rc
ul
at
io
n
pu
m
p
Power supply for Pump
120 VAC
220 VAC etc.
Thermal
relay
120 VAC
220 VAC etc
for relay
These components are NOT included with water
heaters and are external to the unit. They must
be acquired separately.
