COIL AS 1890173 - Caterpillar

Solenoids
On/Off Solenoids
Illustration 9 g01158530Note: The values in Table 11 are for bench testing only. Values may not represent parameters for machine systems specifications.
Table 11
Rated Voltage 24 VDC
Coil Resistance 32.0 3.2Ω (T=20° C) Reverse Proportional Reducing Solenoid Valve
Illustration 10 g02304374
Valve cutaway, hydraulic schematic symbol, and electrical connector designation
Note: The values in Table 12 are for bench testing only. Values may not represent parameters for machine systems specifications.
Table 12
Current Range 0 mA ~ 700 mA
Coil Resistance 11.5 0.5Ω (T=20° C)
Illustration 11 g02304414Reverse PRV's have the P-port open to the A-port with no current applied. Therefore, the machine ECM applies current to the PRV in order to decrease the pressure at the A-port.Hydraulic Lock Solenoid
The hydraulic lock solenoid is an output of the Machine ECM. The hydraulic lock solenoid is energized in order to enable the primary hydraulic pressure. The hydraulic lock solenoid is de-energized in order to disable the primary hydraulic pressure.This solenoid is activated while the key switch is in the ON position and the hydraulic lock lever is in the UNLOCK position.Stick Side Warm Up Solenoid and Boom Side Warm Up Solenoid
Warm-up solenoids are part of the automatic hydraulic warm-up feature and can only be activated with the hydraulic activation lever is in the LOCKED position. The temperature of the hydraulic fluid is monitored by the Machine ECM. If the Machine ECM determines the hydraulic fluid is below the desired temperature, the warm-up solenoids will be energized. The solenoids direct the flow of oil in each of the circuits through an orifice. The increased pressure created by the orifice causes the hydraulic oil to warm up. The oil is passed through the system and returned to the hydraulic tank until the desired temperature is reached.The hydraulic warm-up function can be ENABLED or DISABLED in the monitor.Stick Drift Reduction Valve Solenoid and Boom Drift Reduction Valve Solenoid
When the joysticks are in the NEUTRAL position, the drift reduction valves stop oil leakage. During a BOOM LOWER operation or a STICK IN operation, the machine ECM will energize the solenoid. This action drains the pressure off the back side of the drift reduction valve and the boom and/or stick is allowed to move.For the boom circuit, the drift reduction valve stops oil leakage for the head end of the cylinder. For the stick circuit, the drift reduction valve stops oil leakage for the rod end of the cylinder.Rear Pump Bypass Cut PHMV and Front Pump Bypass Cut PHMV
The pump bypass cut PHMV's are proportional hydraulic modulation valves that adjust the opening of the valve stem based on the inputs to the Machine ECM. The Machine ECM uses the joystick position sensor to determine the position of the bypass valve stem. When the operator is not requesting an implement operation, the hydraulic oil flows through the bypass cut valve stems and returns to the hydraulic tank.The front pump and rear pump bypass cut PHMVs control the standby pressure when all the joysticks are in the NEUTRAL position. When the activation lever is in