GSE Porta-Tronic User manual

Porta-Tronic
Portable Scales
INSTALLATION GUIDE
Version 2.0

GSE Porta-Tronic Installation Guide
Copyright © 2008 GSE. All rights reserved.
Published by:
GSE
1525 Fairlane Circle
Allen Park, MI 48101
www.gse-inc.com
USA
Information in this Installation Guide is subject to change without notice due to correction or enhancement.
The information described in this manual is solely the property of GSE. No part of this manual may be
reproduced or transmitted in any form or by any means, electronic or mechanical, including photocopying
and recording and sold for any monetary figure without the express written permission of GSE.

Table of Contents
1. INTRODUCTION ................................................................................................................................ 1
1.1 TOOLS NEEDED ............................................................................................................................... 1
1.2 UNPACKING..................................................................................................................................... 1
1.3 INSTALLATION................................................................................................................................. 1
2. CALIBRATION ................................................................................................................................... 1
3. LEGAL FOR TRADE.......................................................................................................................... 2
4. TROUBLESHOOTING....................................................................................................................... 2
4.1 LOAD CELL TESTING....................................................................................................................... 2
4.2 TESTING ZERO BALANCE ................................................................................................................ 2
4.3 TESTING BRIDGE RESISTANCE......................................................................................................... 2
4.4 TESTING RESISTANCE TO GROUND ................................................................................................. 2
4.5 LOAD CELL REPLACEMENT ............................................................................................................. 3

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1. Introduction
The scale must not be loaded beyond its capacity. Avoid areas where the scale might receive
damaging side impacts from wheels, forklift tines, etc., or shock damage from falling objects.
1
1. .1 1 T To oo ol ls s N Ne ee ed de ed d
♦1/2” wrench
♦Small screwdrivers (regular and Phillips)
1
1. .2 2 U Un np pa ac ck ki in ng g
Remove packing material and inspect scale for any visible damage caused during shipment. If
damage did occur, notify your freight carrier immediately to register a claim.
Depending on design and packing, some scales are shipped fully assembled. On others, the load
feet and the anchor plate option are shipped separately via UPS.
1
1. .3 3 I In ns st ta al ll la at ti io on n
1. Set the scale or cart on its wheels in an upright position and lock wheel brake(s).
2. Mount the column to the base or cart with hardware provided.
3. Mount the indicator to the top of the column with hardware provided.
4. Connect the load cell cable to the indicator. Refer to the table below for wiring color codes.
Note: Casters with grease nipples should be serviced regularly, especially when the scale
is used in a wash-down environment.
Celtron LOC/LE HBM PW12 Home Run Cable
(+) Excitation Green Blue Red
(-) Excitation Black Black Black
(+) Signal Red White Green
(-) Signal White Red White
(+) Sense Blue Green Blue
(-) Sense Brown Gray Brown
Shield Clear or Yellow
2. Calibration
1. If the indicator and Porta-tronic were calibrated at the factory, the scale is now ready for use.
If the indicator came separately, the scale must be calibrated to the indicator. Refer to the
indicator’s manual for calibration instructions.
2. After calibration has been completed, take known weight (25% of capacity) and check each
corner. Place weight between center of scale and each corner one at a time as shown
below. Use the same calibrated weight in each corner.
3. To adjust corner weight readings, use the trim pot designated for that corner which is
numbered the same as the corner you need to adjust.

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4. After each corner has been checked and calibrated, make a final check of your calibration.
3. Legal for Trade
When the Porta-Tronic is used in a legal-for-trade application, sealing of the scale platform is done using
one of two methods.
♦If a lead wire seal is required, loop the wire through the two holes provided on either end of the
summing box. Add the seal wire after calibration and corner adjustments.
♦If a foil seal is acceptable, apply the foil seal to the outside of the summing box or to the access plate
enclosing the summing box.
4. Troubleshooting
4
4. .1 1 L Lo oa ad d C Ce el ll l T Te es st ti in ng g
Before testing, it is suggested that each load cell be carefully inspected for physical damage.
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4. .2 2 T Te es st ti in ng g Z Ze er ro o B Ba al la an nc ce e
Changes in zero balance usually occur if the load cell has been overloaded. Some change may
be tolerated depending on the application.
Use a voltmeter set to millivolts. Measure the load cell output under no load conditions. It should
be less than 10% of the full scale output.
4
4. .3 3 T Te es st ti in ng g B Br ri id dg ge e R Re es si is st ta an nc ce e
Changes in bridge resistance are most often caused by a failure of a compensating element, a
broken bridge or burned bridge. Usually failure is the result of an electrical transient such as
lightning.
With an ohmmeter, measure the resistance across each pair of input and output leads. The
output resistance of the bridge is normally about 350 ohms for single ended beams and canisters
and 700 ohms for double-ended load cells. Refer to the calibration certificate shipped with the cell
for the actual values. Readings beyond these limits suggest damage and the load cell should be
thoroughly inspected.
4
4. .4 4 T Te es st ti in ng g R Re es si is st ta an nc ce e t to o G Gr ro ou un nd d
Electrical leakage is usually caused by water contamination within the load cells or cables.
Whether the leakage can be tolerated depends on the application and electronic instrumentation
being used. An unstable output is most often caused by contamination.
With a megohmmeter, measure the resistance between all 7 leads tied together (6 live leads and
1 shield) and the load cell body. The reading should be 5000 megohms or more. If the load cell
fails this test, remove the ground wire and test with only the 6 live leads. If it tests good, an
insulation problem is suspected.

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4
4. .5 5 L Lo oa ad d C Ce el ll l R Re ep pl la ac ce em me en nt t
Should a load cell become damaged due to an overload condition, replacement load cells can be
ordered from GSE Scale Systems according to the part numbers in Table 1 on page 3.
1. Unbolt the defective load cell, and then remove leveling load foot from the load cell.
2. Disconnect load cell cable from junction box and attach a chase wire to the load cell cable.
DO NOT CUT THE LOAD CELL CABLE!
3. Pull the load cell cable out of the formed frame channels. The chase wire will be used to pull
the new load cell cable through the formed channel.
4. Install the new load cell by reversing the preceding steps.
5. To verify correct load cell/junction box terminal matching, see the numbers on the terminals
inside the junction box and the corner numbering diagram in Error! Reference source not
found..
6. Position load cell and torque down with a wrench; tighten all mounting bolts to 75 ft./lbs.
7. Route the load cell cables in each corner so that the cable is free from possible contact with
the load cell or load foot. Pull cable tight towards junction box, coil up extra length with cable
ties and securely store inside channel.
8. Pass end of load cell cable through cable fittings in the NEMA 4X junction box. Corner
correction trimming and calibration is necessary after load cell replacement. Follow the
calibration instructions on page 1.
Table 1: Load Cell Part Numbers
Size Load Cell Capacity Part Number Platform
19 x 25
24 x 30
500 lb E0-50459
PT 800 / PT 820 CS
1K E0-50460
2K E0-50460
19 x 25
24 x 30
500 lb E0-50459
PT810 / PT 830 SS
1K E0-50460
2K E0-50462

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Porta-Tronic Installation Guide