mr
.
steam
®
C U S E R I E S
Installation, Operating & Maintenance Manual
28
CHECK
PC Board - Models CU 360, CU 500,
CU 750, CU 1000, CU 1400
1. Prior to checking boiler disconnect boiler electric power
supplies at main safety switch or fuse panel. Turn the
boiler switch OFF.
2. Turn the control voltage ON and turn the boiler switch
ON. Measure the voltage across "L1" and "L2" on the
103538C board. The voltage should be approximately
110 VAC.
3. On the 103538C board, disconnect the wire from the
"LO" terminal and check the voltage across "L2" and
"PUMP". The voltage should be approximately 110 volts
(same as "L1" and "L2"). Connect a jumper between the
"LO" and "GND" terminals. The voltage between "L2"
and "PUMP" should be zero.
4. On the 103538C board, disconnect the wire from the
"LO" terminal. There should be no voltage between the
"L2" and "CONT” terminals. Connect the jumper
between the "LO" and "GND" terminals. The voltage
between "L2" and "CONT" should be 110V.
________________________________________________
Low Water Cutout, Water Feed and
High Water Cutout Probes
Models CU-360 through CU-1400 are equipped with two
probes for low water cut-off (LWCO) and water feed con-
trol. Failure to clean the probes may result in generator
not operating, overflow or element failure.
Turn off all power supplies to
steam bath generator and release pressure to
zero (
0
psig) before removing probes.
1.
Probes are located in the top of the generator. Remove
covers and disconnect wires from probes. Note wire
connections.
2.
Remove probes using a standard spark plug wrench.
Care should be taken not to damage the insulation.
3.
Check probes for deposits. Use emery cloth to clean
probes.
4.
Remove and flush probe isolator (thoroughly) with water.
If clogged, use a long piece of wire to remove obstruc-
tion.
Replace if necessary, center probe rod in isolator tube.
5.
Use teflon tape on probe threads and reinstall.
6.
After installation, make sure probe is not touching
ground. With generator drained and probe wires
disconnected, there should be no resistance (X) between
probe and ground. Check for leaks.
7.
To test AUX LWCO, press and hold the manual reset
button on the side of the steam bath generator for 5
seconds.
Steam Solenoid Valve
1.
Check voltage rating of solenoid valve (120 VAC for
United States, Canada, Mexico; may be 220-240 VAC
for other countries).
2.
Check voltage across solenoid coil.
a. If there is voltage across coil and valve does not
allow passage of steam, check for clogged valve.
Clean outline with bottle brush. If solenoid valve is
still malfunctioning, the valve is defective and should
be replaced.
b. If there is no voltage across coil, check room tem-
perature control.
c. There wull be a red dot under “OUT2” on the
Digital 1 Control when there is a call for heat.
d. Ensure, if equipped, the room Timer is On.
_______________________________________________
Digital 1
®
Control and Sensor:
Consult Factory
_______________________________________________
Heating Element
IMPORTANT:
Turn off all power at circuit break-
er. Consult factory for resistance values.
1.
Check power voltage across heating element terminals.
Refer to nameplate data for voltage rating.
Voltage should be as marked on nameplate.
2.
Using an ammeter, measure total current draw as per
nameplate rating. (See also Amperage Chart, page 8.
Each leg should register about the same current read-
ing.
3.
If there is more than one heating element, check
amperes of each element. Each leg of the same ele-
ment
should register about the same reading for that ele-
ment. Reading may be different from other elements
due to KW (Kilowatt) rating of individual heating ele-
ment.
4.
Check heating element for resistance values. Consult
factory for the resistance values for the element specifi-
cations.
Prior to checking boiler disconnect boiler
from electric power supply at main safety switch or
fuse panel. Turn boiler switch to OFF.
CAUTION
!
CAUTION
!
CAUTION
!
