INSTALLATION, OPERATING AND TROUBLESHOOTING INSTRUCTIONS FOR MODEL A75D / A75DE –
THREE PHASE
Page 13 of 20
ELECTRICAL CONNECTIONS & FIELD WIRING
A terminal board is provided for connecting the AC input and DC output. A ground wire must be
connected to the unit’s case ground.
AC INPUT
Make sure that AC power is off at the main AC breaker box before installation begins.
Make sure that the input source is the same voltage and frequency as that which is marked on the
nameplate of the rectifier.
The wire size and distribution protection should be adequate for the nameplate input current of the
rectifier plus the overload current (usually 10%-15% higher than the nominal rating).
An adequate earth ground lead should be connected to the terminal marked “GROUND” or “GND”.
DC OUTPUT
Make sure that the battery voltage, which is being connected to the rectifier, matches the rectifiers
output voltage.
*****OBSERVE PROPER POLARITY!*****
The negative wire from the battery must be connected to the terminal marked “NEGATIVE” or “NEG” and
the positive wire from the battery must be connected to the terminal marked “POSITIVE” or “POS” on the
rectifier.
To prevent the DC output breaker from tripping when connecting the battery, connections to the power
supply and batteries should be done in the following order (single power supply).
1.
Connect AC input line to the terminal block provided. Be sure the AC circuit breaker is off.
2.
Observe the polarity of the battery cables and the rectifier output. Connect the negative battery cable to the
negative rectifier output terminal.
3.
Energize the unit by turning the AC breaker to the “ON” position. This will charge the capacitors inside the
power supply and eliminate heavy arcing when the remaining battery cable is connected. After approximately
one (1) minute, turn off the power supply and immediately connect the remaining battery cable.
4.
Connect the loads.
5.
Turn the AC breaker to the “ON” position again and the rectifier will commence charging the batteries and
powering the load.
LOAD SHARING
A load sharing circuit is provided as a standard feature of the A75D/A75DE. When connected two (2) or
more identical A75D/A75DE units are forced to share the load equally (less than +/- 5%). To load share,
connect the unit outputs (must be the same DC voltage) in parallel and connect the LS terminals
together. If the charger is equipped with a Remote Equalize Terminal, connect the RE terminals
together. The remote equalize connection forces the chargers to enter equalize mode at the same time.
GROUND DETECTION
If ground detection is desired, the green wire should be installed in the GND DET terminal of J9 terminal
block of the S2A-362 control PCB. To disable, move wire to GND DET DEFEAT terminal of J9.
