Troubleshooting, Diagram 1 diagram 2, Diagram 3 diagram 4 – Xylem MM 214E Series 61 Low Water Cut-Off User Manual
Page 6
6
0
2
0
4
1
0
3
0
0
2
0
4
1
0
3
0
0
2
0
4
1
0
3
0
SCHEMATIC OF TWIN SWITCH
INTERNAL OPERATION
NORMAL WATER LEVEL
FEEDER OR ALARM
OPERATING LEVEL
LOW WATER CUT-OFF
OPERATING LEVEL
NEUTRAL WIRE
NEUTRAL WIRE
HOT WIRE
HOT WIRE
TO BURNER
TO ALARM
SAFETY
SWITCH
0
2
0
4
1
0
3
0
USED AS MAIN LINE SWITCH
Diagram 1
Diagram 2
TO LINE
TO BURNER
STARTER
NO. 11
SWITCH
L1
L2
L3
0
2
0
4
1
0
3
0
USED AS PILOT SWITCH IN SERIES WITH
HOLDING COIL OF AUTOMATIC STARTER
NEUTRAL WIRE
TO
TWO WIRES OF 101A
OR TO ALARM CIRCUIT
HOT WIRE
TO BURNER
JUMPER
NO. 11
SWITCH
0
2
0
4
1
0
3
0
USED WITH MODEL 101 ELECTRIC
WATER VALVE OR IN ALARM CIRCUIT
Diagram 3
Diagram 4
IMPORTANT: Low water cut-off circuit of the 61 series must be electrically wired in series with all other boiler
limit operating controls.
TROUBLESHOOTING
Problem:
1. Burner does not shut off on low water.
a. Cause: Float chamber is loaded with mud or
sediment.
Test: With water level below the control
check if terminals 1 and 2 are open. If
not, remove switch and manually test if
terminals 1 and 2 can be opened.
Solution: Open float chamber and clean. At this
time, check for a build-up of scale or
sediment between corrugations of the
bellows.
b. Cause: Contacts are fused together.
Test: Remove switch and operate manually to
verify proper switch operation.
Solution: Replace switch. Check electrical load
and make sure it is within the ratings of
the switch.
2. Electric water feeder does not shut off.
a. Cause: Build-up of scale or sediment between
corrugations of the bellows.
Test: With water level above the control,
check if terminals 3 and 4 are open. If
not, remove switch and manually test
to verify terminals 3 and 4 can be
opened.
Solution: Open float chamber and replace or
clean the bellows.
b. Cause: Contacts are fused together.
Test: Remove switch and operate manually
to verify proper switch operation.
Solution: Replace switch. Check electrical load
and make sure it is within the ratings of
the switch.
MM-214(C) 9/5/06 9:40 AM Page 7