Avery Weigh-Tronix FLI 225, Service Manual

Page: 102 / 110

102 FLSC 05 w/FLI 225 Instrument Service Manual
10.9 Forklift Scale Grounding
To prevent future issues for the forklift scale or its components it is recommended that
forklift scale grounding be tested.
This test will determine if the forklift scale is properly grounded by the forklift truck.
Improper grounding can cause damage to the electrical components of the indicator
and its peripheral devices.
10.9.1 Testing Procedure
1. Measure the voltage between the lift truck + and – battery terminals and then
measure the voltage between the + terminal of the battery and the lift truck
chassis. The voltage readings should be the same (within .05 VDC).
If this voltage does not match, the truck battery ground and chassis
ground are not connected properly. It is the technician’s responsibility to
inform the end user of the grounding issue and end user is responsible
to fix the problem.
2. Measure the voltage between the + terminal of the battery and a spot on the
scale carriage assembly that allows you to connect the probe to bare metal.
You should see the same voltage as in step 1.
3. If this voltage does not match, the scale carriage is not getting a proper ground
connection to the lift truck chassis. It is the technician’s responsibility to fix the
problem.
4. To correct this problem a grounding strap/wire (minimum 4 AWG) will need to
be connected from the scale carriage to the lift truck carriage plate. Due to
forklift truck make, model and options, a grounding strap/wire will need to be
sourced locally to ensure proper fitting.
There are ¼-20 pre-tapped holes on the sides of the scale carriage opening
that can be used to connect the grounding strap. See the picture below for
location of these holes.
Re-measure the voltage readings to confirm the problem is corrected.
If the lift truck carriage is mounted on a side shifter, the grounding strap or wire needs
to connect to the stationary plate of the side shifter. This is required since the side
shifter might become intermittently or partially isolated from lift truck chassis ground
during movement. Make sure that the ground strap or wire has free range of
movement during operation of the side shifter.