Page 294 - Electronic Mechanic - TP - Volume - 2

ELECTRONICS MECHANIC - CITS

• AC POWER SUPPLY. Check phase and voltage of AC power supply. These should correspond to AC
ratings of the unit, which is stamped on the nameplate.
• DC CIRCUITS. Zero the DC meters. External DC load should be in proper operating condition. Connect
ground bed (anodes) to positive (+) DC output terminal. Connect structure to be protected to negative (-)
DC output terminals.
• CONNECTIONS. Make sure all connections to and in your Universal Rectifier are tight. Where Universal
voltage tap changer is used, voltage tap adjusting knobs need only be hand tight.
3 To place your universal rectifier in the constant current operation:
When in operation, the actual DC voltage and current output of the Universal Rectifier are indicated by the
meter select switch for the LCD meter on the instrument panel of the rectifier. Care should be taken that these
meter readings do not exceed either the DC voltage or DC current ratings of the unit. If ratings are exceeded,
simply turn the corresponding current adjust rheostat counter clockwise until unit is operating in designed
limits.

• The voltage/current link bar must be on the current side. Turn all current adjust rheostats to highest setting
(clockwise) and set all coarse and fine taps to a setting slightly above the current you want to maintain.
• Turn external AC power supply “ON”.

• Close circuit breaker or safety switch of rectifier (“ON” position).
• Check DC ammeter and voltage readings on instrument panel.
4 To adjust dc current:
The following steps should be followed in sequence observing precautions in steps I, II and III until desired DC
current is attained.
• With the coarse and fine tap link bars set in the position slightly above the current you want, decrease
output current adjust knob counter clockwise till desired current is obtained. The rectifier will now maintain
the current setting.
5 To place your universal rectifier in the constant voltage operation:
When in operation, the actual DC voltage and current output of the Universal Rectifier are indicated by the
meter select switch for the LCD meter on the instrument panel of the rectifier. Care should be taken that these
meter readings do not exceed either the DC voltage or DC current ratings of the unit. If ratings are exceeded,
simply step down the coarse and fine taps until unit is operating in designed limits.
• The voltage/current link bar must be on the voltage side. Note: all current adjust rheostats will now be out
of the circuit. Set all coarse and fine taps to a desired setting.

• Turn external AC power supply “ON”.
• Close circuit breaker or safety switch of rectifier (“ON” position).
• Check DC ammeter and voltage readings on instrument panel.
6 General maintenance instructions
• Voltage, current and ambient temperature ratings of unit should not be exceeded.

• Routine cleanliness should be maintained.
• Adequate ventilation must be provided - screened openings should be kept free of obstructions.
• All electrical connections should be tight.
• Severe overloads can permanently damage rectifiers and special precautions may be required for abnormal
or persistent overload exposures.
• For oil immersed units, oil should be inspected periodically. Oil should be replaced when contaminated.
7 Maintaining desired current and voltage
The rectifier unit will respond to electrical changes in the system external to the unit. Such as pronounced
fluctuation of the AC line voltage or changes in ground bed resistance. Such changes can alter the operating

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CITS : E & H - Electronics Mechanic - Exercise 202&203