UTICA BOILERS UB90-200 Installation, Operation & Maintenance Manual page 19

Figure 14B -Ladder Wiring Diagram
NOTE: If any of the original wire as supplied with this appliance must be replaced, it must be replaced with type 150°C
Thermoplastic wire or its equivalent.
P7-1
2K1 P4-1
P10-1
1K1
P5-1
5K1
P6-1
P1-1
P2-1
(MANUAL RESET)
P3-9
P3-7
R W
THERMOSTAT
ON/OFF
SWITCH
LWCO
(PS-122)
BLOWER
P12-1
CASTING TEMPERATURE
SAFETY SWITCH
4K1 3K1
P3-1
DIFFERENTIAL
1
AIR PRESSURE
SWITCH (N.O.)
3
SET AT
2
+ 0.5" WC
1
P3-3
P3-6
HIGH LIMIT
AQUASTAT
CONTROL
P3-4
ELECTRICAL WIRING
120 VOLT POWER SUPPLY
(NOTE: USE COPPER CONDUCTORS ONLY)
L1
HOT
BLK WHT
CIRCULATOR FIELD WIRED
HOT SURFACE IGNITER
120 VAC
3 1
TRANSFORMER
4 5
24 VAC
GAS VALVE
P3-5
MICROPROCESSOR
ELECTRONIC
LOGIC & TIMERS
INDICATOR LIGHTS
1013-10 CONTROL
19
L2
P4-3
P10-2
P10-3
P12-2 P6-2
5K2
P1-3
P2-2
P3-2
5K
4K
POWER
3K
PURGE
2K
IGNITER
1K
VALVE
FLAME
P1-2
P7-2
P7-3
P5-3