High Pressure Cutout Switch - TM-5-4110-217-140027

TM 5-4110-217-14

Protective Cutout Switches.

the knob clockwise to lower the box temperature or

counterclockwise to raise the box temperature. After the

(1) A cranking limit switch (fig. 2-5) interrupts

desired temperature is preset on the thermostat scale,

power to the starting motor if the engine falls to start after

the operation of the thermostat is automatic.

a 30 sec. cranking period of time. The cranking limit

b. On-Off Switch (fig. 2-3).

switch is part of the printed circuit board mounted in the

(1) General. This is a double-pole, double-

control box.

(2) The low-oil pressure switch (32, fig. 3-11)

throw switch mounted on the control panel and is

disconnects the alternator when the engine is not

connected in the control circuit. When the switch is

running. The low-oil pressure switch is located on the

placed in ON position, the circuit is through the high-

engine crankcase chassis behind the flywheel.

pressure cutout, thermostat, and coil of the motor starter.

(3) The magnetic starter (5, fig. 8-3) in starter

In this position, the unit will run on thermostat demand.

(2) Operation. The operation of this switch is

mounting box will open the power circuit to the electric

motor under overload conditions.

manual. The switch is not adjustable and must be

h. Hourmeter. An hourmeter which records the

replaced if defective.

High Pressure Cutout Switch (fig. 2-4).

running time of the unit is located on the control panel

(fig. 2-3). It is in operation as long as the temperature

(1) General. The high pressure cutout switch

control switch is closed.

consist of an electric switch and a pressure-operated

bellows The switch is wired into the control circuit and the

bellows is connected by tubing with the discharge side of

2-10.

Operation of Equipment.

the compressor. When the pressure of refrigerant rises

WARNING

to a preset limit, the bellows is moved enough to open

the electric switch and stop the unit.

If equipment fails to operate, refer

(2) Operation. Cutout and differential scale

to troubleshooting procedures in

settings are preset by the manufacturer before the

Chapter 3.

refrigerating unit is shipped. These settings are 250 lbs

for the high pressure side of the scale and must be

a. The instructions in this section are published

manually reset if a high pressure condition occurs

for the information and guidance of the personnel

d. Compound Pressure Gage (fig. 1-1).

responsible for operation of the refrigeration unit.

(1) General. The section pressure gage is a

The operator must know how to perform every

special compound gage with a dial graduated to record

operation of which the refrigeration unit is capable. This

pressure range from 30-inch vacuum to 150 pounds per

section gives instructions on starting and stopping the

square inch. This is a special water-proofed gauge with

refrigeration unit, basic motions of the refrigeration unit,

a bronze brushed movement Refrigerant pressure will

and on coordinating the basic motions to perform the

vary with the temperature in the box The suction

specific tasks for which the equipment is designed.

pressure will vary between 8 pounds and 10 pounds.

Since nearly every job presents a different problem, the

(2) Operation.

Operation of the suction

operator may have to vary given procedures to fit the

pressure gage is automatic.

individual job.

e. High Pressure Gage (fig. 1-1)

(1) General.

The high pressure gage is

2-11.

Starting the Equipment.

incorporated in the refrigerant system to facilitate reading

the pressure in the discharge side of the compressor.

a. The RMP-J/11-1OE electric motor powered unit

This gage has a graduated scale reading from 0 to 300

(fig 2-1, sheet 2) requires a source of 208-volt, 3-phase,

pounds per square inch.

60 hertz alternating current for operation. Make sure that

(2) Operation. Operation of the high pressure

the fans rotate in the proper direction for correct air flow.

gage is automatic.

Reverse power leads to reverse direction of motor

Dial Thermometer

rotation.

(1) General. A dial thermometer (fig. 1-1) is

b. The RMP-J/1-1OG, Gasoline powered unit can

mounted on the left edge on the front of the unit.

be rope started.

(2) Operation. This thermometer indicates

(1) After servicing the gasoline powered unit

the temperature of air inside the refrigerated box.

for normal starting as prescribed in daily preventive

maintenance services.

(2) Be sure the battery is installed even when

in a discharged condition.

(3) Place the power switch in the on position.

Thermostat to coldest setting.

(4) Wind the start rope around the rope start

pulley on the flywheel.

Change 3 2-4