Murphy EL150EX - Manual (Page 3)

L-7758N page 3 of 4
LEVEL SWICHGAGE ® INSTALLATION (continued)
For a PRESSURIZED system the tip of the copper tube will be the
shutdown level.
3. For ATMOSPHERIC
(non-pressurized) and
PRESSURIZED CROSS FLOW
COOLING SYSTEMS the
shutdown point is determined by
the mounting position of the
L150/EL150K1 relative to the top
tank of the radiator (see step 5).
4. For a PRESSURIZED SYSTEM,
determine the point of entry (tube
connection) in the radiator top
tank (away from the top hose
connection). Many radiators have
a pipe nipple provided. If a
connection is not provided, you must either weld or solder a fitting or
use one of the Murphy PS fittings (see PS Fittings Installation page
2). This connection should be as close to the radiator core as possible.
For MARINE AND MOBILE EQUIPMENT installations, the top
tank connection should be near the vertical centerline of the radiator.
This will compensate for changing level due to roll and pitch of the
machine during operation.
5. For an ATMOSPHERIC SYSTEM a tube connection in the top tank
may not be required. Determine the lowest desired level of coolant in
the top tank. Mount the L150/EL150K1 so that the mounting ears are
approximately 1/4 in. (6 mm) above that level (Figure 3).
A back mounting option is available for the L150 and EL150K1 for
radiators with fabricated steel top tank and/or for use with some
condensor cooling systems.
For an ATMOSPHERIC system install a 1/4 in. (6 mm) diameter
tube in the top fitting of the L150/EL150K1. This tube MUST
EXTEND ABOVE the top tank. Form the tube into a cane so that the
open end of the tube points down but still extends ABOVE the
HIGHEST coolant level. The tube can be connected to the top tank if
desired. Follow instructions for a PRESSURIZED SYSTEM.
6. For most applications, the bottom tube connection is made at the drain
cock. Remove the drain cock and install a brass tee. Reinstall the
drain cock into the tee. Attach a copper or other suitable tube to the
remaining opening of the tee and to the bottom connection of the
L150/EL150K1.
If a drain cock is not provided, you must attach a fitting or use a
Murphy PS fitting the same as for the top tank instructions.
7. Wire according to appropriate alarm or shutdown circuits (see
Standard Electrical Diagrams on page 4).
8. Refill the cooling system according to manufacturer’s instructions.
9. Start the engine and allow it to run until the thermostat opens.
Increase engine speed to the FULL operating speed and observe that
the indicating pointer remains at or near the full position. If the
pointer drops to the LOW position shutdown or alarm will occur due
to coolant flow through the L150/EL150K1. If alarm or shutdown
occurs, drain the coolant - or clamp off the upper and lower hoses.
CAUTION:
BE SURE SYSTEM PRESSURE IS RELIEVED
AND HOT COOLANT CANNOT ESCAPE. Remove the four (4)
mounting screws holding the cover assembly. Invert the float chamber
so that the 1/2 NPT connection is on top and the 1/4 NPT connection is
on bottom. Reinstall the float and cover assembly in the upright
position. Install larger I.D. tubing from the top of the float chamber
(1/2 NPT) to the radiator top tank. The smaller 1/4 NPT connection on
the bottom will restrict coolant outflow from the L150/EL150K1.
Check for unrestricted float movement by rotating the switch test knob.
Refill the cooling system and repeat step 9.
10. Place a catch basin under the drain cock. Open the drain cock and
observe that coolant is leaving the radiator.
For a PRESSURIZED cooling system, shutdown will occur when
coolant drops below the entry point of the top tank tube connection.
For an ATMOSPHERIC OR CROSS FLOW PRESSURIZED
COOLING SYSTEM, shutdown will occur when coolant drops
approximately 1/4 in. (6 mm) below the level of the case mounting ears.
If shutdown does not occur, adjust the L150/EL150K1 mounting as
described above.
CAUTION: DO NOT ALLOW ENGINE TO RUN WHEN
COOLANT DRAINS BELOW THE UPPER TANK. ENGINE
DAMAGE CAN OCCUR.
11. Periodically test switch operation by rotating the test knob on the face of
the L150/EL150K1. Rotating the knob forces the pointer mechanism
against the contact screw (L150) or the snap switch actuator (EL150K1).
Condensor/Radiator System
1. Mount the L150/EL150K1 so that the horizontal center line of the
L150/EL150K1 is approximately 1/4 in. (6 mm) above the minimum
coolant level in the engine head.
NOTE: On some engines it is possible to use
the back connection option and attach the
L150/EL150K1 directly to the engine
cylinder. Kits are also available for some
engines.
2. Attach a copper tube from the top
connection of the
L150/EL150K1
to the radiator top tank.
3. Wire and test the
system according to above
instructions for Pressurized
and Atmospheric systems.
Figure 3:
Deep Upper Tank
Figure 2:
Shallow Upper Tank
Normal
Coolant
Level
Mounting
Ears
Low
Level
Shutdown
Point
Low
Level
Shut-
down
Point
Figure 4: Atmospheric System
Figure 5:
Condensor/Radiator System
Low Level
Shutdown
Point