L404F,T,V PRESSURETROL® CONTROLLERS
OIL PRESSURE
CONTROLLER (AT RIGHT ANGLES TO THE MAIN PIPE LINE) 
All wiring must comply with applicable codes and ordinances. All models have terminals (on the MicroSwitch®
L404F PRESSURETROL
HEXAGONAL
FITTING
PIPE NIPPLE
PIPE
WRENCH
MAIN TEE (TURN TO LEVEL THE CONTROLLER)
MAIN PIPE LINE 
R
W
B
L1
POWER (HOT)
SUPPLY
1 L2
2
24 VOLT RELAY
M17860
Fig. 4. Mounting an oil pressure controller
directly on the main pipe.
Using with Preheated Oil
When used with preheated oil, a siphon loop (part number 14026) must always be connected between the controller and the main pipe (see Fig. 5) to provide thermal buffering.
OIL PRESSURE
CONTROLLER
24 VOLT |
POWER |
SUPPLY |
1PROVIDE DISCONNECT MEANS AND OVERLOAD PROTECTION AS REQUIRED.
2AS SHOWN, SWITCH OPENS ON PRESSURE RISE. REVERSE ACTING (MAKE ON PRESSURE RISE) UNITS ARE WIRED TO
M19637A
Fig. 6. L404F in low voltage relay circuit.
TO
(114 TO
140)14026
SIPHON LOOP 1
TEE
PREHEATED OIL SUPPLY LINE
1 1/4 INCH BLACK IRON PIPE WITH
BOTH ENDS AND | M17858A |
|
LINE VOLTAGE THERMOSTAT
L1 L2 (HOT)
POWER SUPPLY 1
L404F PRESSURETROL
2
R
W
B
MOTOR
Fig. 5. Mounting of a siphon loop, with approximate
dimensions in in. (mm).
WIRING
WARNING
Electrical Shock Hazard.
Can cause severe injury, death or property damage.
Disconnect the power supply before beginning wiring. More than one power supply disconnect may be required.
1PROVIDE DISCONNECT MEANS AND OVERLOAD PROTECTION AS REQUIRED.
2AS SHOWN, SWITCH OPENS ON PRESSURE RISE. REVERSE ACTING (MAKE ON PRESSURE RISE) UNITS ARE WIRED TO
M19638A
Fig. 7. L404F in a typical 2-wire control circuit.
5 |