User's Manual

Troubleshooting
26 313540G
Pumps Do Not Reverse Direction
1. For the proportioning pumps to reverse direction,
the switch disk must contact the reversing switches.
Ensure that the change over box is assembled cor-
rectly and that none of the components are dam-
aged. See F
IG. 1 (page 25) and Parts (page 58).
2. Check the function of the directional valve. Direction
indication lights should switch on and off based on
the position of the reversing switches (199). LEDs
D19 and D20 (near J5 reversing switch connector
on motor board, see F
IG. 6) should alternately illumi-
nate when each switch is activated.
There are two possible problems with the directional
valve:
a. If D19 and D20 do not alternately illuminate, the
possible causes include:
• faulty reversing switch wiring,
• faulty reversing switch, or
• faulty motor board.
To resolve this problem:
• verify that the reversing switch cable is con-
nected at the bulkhead bracket and that it is
plugged into the J5 connector on the motor
board.
• verify reversing switches. Unplug the J5
reversing switch connector. Verify that when
the switches are not triggered there is conti-
nuity between 1150-NC and 1160-T-COM,
and between 1150-NC and 1170-B-COM.
Toggle reversing switches. Ensure that con-
tinuity between 1150-NC and 1160-T-COM,
and between 1150-NC and 1170-B-COM is
lost. Refer to the Electrical Diagrams man-
ual 312064 (Detailed Schematic, Motor
Controls (3-Phase Motor)). If these four
conditions are not verified, replace revers-
ing switches.
• if the reversing switch and wiring are not the
cause, and D19 and D20 will not alternately
illuminate, replace the motor board.
b. If D19 and D20 do illuminate but the direction
indication lights do not, the possible causes
include:
• faulty motor board,
• faulty directional valve wiring, or
• faulty directional valve.
To resolve this problem:
• verify the motor board output voltages at the
J18 directional valve connector. When the
reversing switch is toggled one direction,
there should be 230V output between pins
1 and 2 (A+ and A-). When it is toggled the
other direction, there should be 230V output
between pins 3 and 4 (B+ and B-). If output
voltages are not present, replace the motor
board.
• verify continuity of each directional valve
wire and verify wiring connections (see
Electrical Diagrams manual 312064).
• if motor board and wiring are not the cause,
replace the directional valve.
NOTE: For diagnostic purposes, it is possible to
manually override the directional valve by using a
small screwdriver to depress the button in the cen-
ter of either directional valve end cap.
F
IG. 2: Hydraulic Directional Valve Assembly
r_256886_313540_1
Directional Valve