4. CALIBRATION AND MAINTENANCE
ALPHA C-20/25 CHARGER – OPERATING MANUAL V1.0
Page 15
4. CALIBRATION AND MAINTENANCE
4.1 OVERVIEW OF CALIBRATION
The Alpha C-25 has been calibrated before shipment from the manufacturer. A
certificate of calibration with test instruments traceable to the National Institute of
Standards and Testing in accordance with MIL-I-45208A has been issued and is
enclosed in the back of this manual. To ensure error-free operation over time,
calibration should be verified every 12 months depending on usage and changes in
surrounding environment.
4.1.1 DIGITAL PANEL METERS
There are two main indicators that can be periodically verified: 1) the voltmeter;
and 2) the ammeter (see figure 1-1 in section 1). In addition the internal shunt,
even though calibrated and certified by the shunt manufacturer, could be verified.
4.1.2 TIMER
The timer is a very accurate crystal-controlled device, not prone to error. It cannot
be re-calibrated, but unless an extremely accurate time reading is required, an
accurate analog or digital stop watch is adequate to validate its accuracy.
4.1.3 OPERATING RANGES
The Alpha C-25 gives the capabilities to modify the charge voltage in constant-
potential mode as well as the voltage limit in constant-current mode.
WARNING:
Calibration should only be performed by
trained personnel. If performed incorrectly it could result in
electrical shock leading to injury or death.
The Alpha C-25 Battery Charger now includes external test point jacks
for voltage and current verification.
Voltage Verification – Do not connect C-25 to battery. Select 28.5 V
setting. Using an external calibrated digital meter (set to DC Volt
scale), connect to voltmeter test jacks and verify voltage panel meter
is within approximately 0.3 volts.
Current Verification - Connect C-25 to battery and discharge
at approx. 20 Amps. Using an external calibrated digital
meter (set to millivolt scale), connect to ammeter test jacks
and verify panel meter is within approx. 0.3 Amps.
Summary of Contents for ALPHA C-20
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