Greer Company
Greer Company
Greer Company
Greer Company
Crane Systems
1918 EAST GLENWOOD PLACE, SANTA ANA, CA 92705
Tel: (714) 259 9702 Fax: (714) 259 7626
MicroGuard
424 Operation/Troubleshooting Manual Horizontal Display Hydraulic Cranes
34 of 52
W424103 REV A 02/13/01
PRESSURE CHANNEL FAULT GUIDE
PRESSURE CHANNEL FAULT GUIDE
PRESSURE CHANNEL FAULT GUIDE
PRESSURE CHANNEL FAULT GUIDE
FUNCTIONAL TESTS
A fault in a pressure transducer is such that a fault on
one channel can cause an apparent fault in the other
channel. It is necessary to test both channels and both
transducers together in order to determine which
transducer is at fault.
1. Access the calibration routine by simultaneously
pressing and holding
SELECT (1) and TEST (2) keys
The display will request entry of the calibration
security code.
2. The security code is entered by the consecutive
pressing of the calibration arrow keys which MUST
be in the following sequence:
Up, (3), Down (4),
Left (5), Right (6),
SELECT
(1)
If the wrong sequence is used, or if the entry is not
completed within 5 seconds, the calibration entry will
be aborted and must be re-entered. After accessing
the calibration routine, the system alarm will sound
as a reminder that the calibration routine is active.
3. Use the Up (3) or Down (4) Arrow keys to scroll to
command 06 Zero. Press Select (1).
4. Press the Left Arrow (5) and then use the Up (3) or
Down (4) Arrow keys to select TX 0 (pressure
transducer 0 piston side). Press Select (1).
5. With the boom in the rest or the boom hoist cylinder
fully retracted, relieve all pressure from both
transducers. With no pressure, the upper display
should indicate 0+/-20 bits.
6. Press the Left Arrow (5) and then use the Up (3) or
Down (4) arrow keys to select TX1 (pressure
transducer rod side). With no pressure in the
cylinder, the upper display should read 0+/- 20 bits.
7. If the transducers were disconnected in step 5,
tighten the fittings. With the boom fully retracted,
boom up to a 60° angle.
8. Access the Zero of TX 0, as described in step 5.
The upper display should read 200+/-100 bits.
9. Access the Zero of TX 1, as described in step 7.
The upper display should read 5+/-25 bits.
10. Boom down. As the boom is moving down, the
displayed bits of TX 1 should increase.
11. Place the retracted boom at a 60° angle. Access the
Zero of TX 0, as described in step 4, and extend the
boom. As the boom is extended, the displayed bits of
TX 0 should increase. When the boom is fully
extended, the display should read 400+/-100 bits for
a three-section boom and 600+/-100 bits for a four-
section boom.
The values listed are nominal values. The actual
values will differ according to how the crane is
equipped. A three-section boom will show a smaller
value on TX 0 under the same conditions as a four-
section boom. Additional equipment on the main
boom, such as stowed fly, auxiliary head sheaves
and hook blocks will give a higher value than the
main boom alone. If any value is out of range,
contact your distributor or factory service department
before replacing a pressure transducer. Refer to
page 43 of this manual for pressure transducer
replacement.
12. Exit the calibration routine by pressing the TEST (2)
key.
If the foregoing functional tests indicate faults in the
pressure channels, proceed with Power Supply
Tests and the test of the resistance of the bridge of
the pressure transducers.
TEST
MicroGuard 414
INFORMATION
100%
OPERATOR ALARMS
CONTRAST
VIEW
SET
CLEAR
DOWN
UP
CRANE
SET UP
STOWED
DEDUCT
WORKING
AREA
DEDUCT
ERECTED
STOWED
SELECT
W
W
MAX
1
2
3
4
5
6
