MULTISKAN RC and
MS
SERVICE MANUAL
CHOPPER SPEED IS TOO HIGH
Reason: During startup and before each measurement the instrument checks thatthe chopper
speed is within range 1200 to 1500 rpm. If the speed is higher, this error is reported.
Action: Contact service.
Service:
Open theinstrument cover andpower up the instrument. Connect an oscilloscope
to test points XI0 (ground) and XI1 (signal) on the MUSCU-RC board.
Chopper sensor signal should
be
visible on the scope. Locate the adjusting
potentiometer R3 on the CHOPT board. Turning the potentiometer clockwise
with a screwdriver should reducechopper speed andcounterclockwise increase.
If
nothing happens there is
a
fault in the electronics on the CHOPT board.
Measure voltage at pin 6 of N1. It should be 6.8..7.5 V.
If
not, the faulty
component likely is N1. With the oscilloscope, observe pin 3 of N3. A pulse
outputwith same frequency as test pointX11 should be present. If not, the faulty
component likely isN3. With ajumper wire,connectpins 4 and6of N1 together.
If the chopper does slow down, faulty component is V1 or possibly N1.
When the problemis
fixed,
adjust cycle time at test point XI1 to as close to 5.1
ms as possible, rather more than less.
Chopper speed can also
be
adjusted without an oscilloscope using STATUS
command to observe chopper speed. Adjust to 1440
...
1470 rpm.
CHOPPER SPEED IS TOO LOW
Reason:
During startup and before each measurement theinstrument checks that the chopper
speed is within range 1200 to 1500 rpm.
If
the speed is slower, this error is reported.
Action: Contact service.
Service: Open the instrument cover and power up the instrument. Fist check that there is
more than 20
V
voltage between pins 7 and 12 of N1 on the CHOPT board.
If
the
chopper does not rotate at all, briefly connect with a jumper wire pin 11 of N1 to
the terminal with red wire on the chopper motor.
If
the chopper does not start, the
motor is faulty. Connect pins 5 and
6
of N1 together. The chopper should speed up.
If
not, V1 or possibly N1 is faulty. Connect an oscilloscope to test points XI0
(ground) and XI1 (signal) on the MUSCU-RC board. Chopper sensor signal
should be visible on the scope. If not, the sensor is faulty. Locate the adjusting
Document Release
,--
Section Page
3511352-100-x
1
.O
-:--
Labsystems
8
13
Artisan Technology Group - Quality Instrumentation ... Guaranteed | (888) 88-SOURCE | www.artisantg.com
To Next Page
Loading...
