OHAUS EC Series, Service Manual

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1-2
CHAPTER 1 INTRODUCTION
1.2 TOOLS AND EQUIPMENT
1.2.1 Standard Tools and Test Equipment
The service shop should contain the following equipment:
1. Digital Voltmeter (DVM).
2. Standard Electronics tool kit.
3. Desk magnifier on a stand.
4. Grounding mat and clip.
5. Razor blades.
1.2.2 Special Tools
To service the Ohaus EC Series Scales, the following equipment is recommended:
1. A Load Cell Simulator.
2. AC Adapter, 220 V, 60 Hz (US) Ohaus P/N 80120000
3. AC Adapter, 230 V, 50 Hz (EU) Ohaus P/N 80120001
4. AC Adapter, 230 V, 50 Hz (GB) Ohaus P/N 80120002
5. AC Adapter, 240 V, 50 Hz (AU) Ohaus P/N 80120003
6. AC Adapter, 100 V, 50 Hz (JP) Ohaus P/N 80120004
7. AC Adapter, 230V, 50 Hz (KR) Ohaus P/N 80120025
NOTE : Adapters required for servicing are location dependent.
1.3 CALIBRATION MASSES REQUIRED
The masses required to test the EC Series Scales must meet the requirements of ASTM Class 4 or OIML
Class F2. The mass values are listed in Table 1-1.
TABLE 1-1. CALIBRATION MASSES
MODEL Calibration
Cal in kg: Masses Totaling
EC3 3kg
EC6 6kg
EC15 15kg
EC30 30kg
Note: The EC Scales can be calibrated over a wide range, however, it is recommended that the
calibration mass used is at or near the full capacity of the scale for maximum accuracy.
1.4 SERVICE STRATEGY
The repair method for the EC Series Scales is the direct substitution of major assemblies. The available
repair parts are listed in Table 5-1.
The EC Series Scales contains 6 major replaceable assemblies: Top Housing, Membrane Switch, Load Cell
Assembly with Frame, Lead Acid Rechargeable Battery, Display PC Board with LCD and the Main PC
Board.
NOTE : The Load Cell and LCD may also be ordered and replaced separately.
This service manual contains sufficient information to isolate the problem, replace the component, test
and restore the Scale to original factory specifications.