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installation instructions
bcu battery charger
CHARGING OPERATION
1. Connect battery charger to battery. Energize battery
charger. For charging status, refer to BCU interface.
•Ammeter
The BCU is not congured for output scaling during bulk
charging phase. Ammeter lights may not apply to BCU
charging operation.
•Bulk Charge Indicator
Displays solid when batteries have reached 80% charged
status.
•AC Indicator
Displays when AC power is present. If ashing, low AC
voltage is present.
•Charge Completion
Batteries have reached 100% charge status. BCU will
now apply charging as needed.
•Fault Indicator
A charger error is present. Battery charging may not
occur normally.
TROUBLESHOOTING
AC Indicator
Off
Problem No AC power connected
Possible
Cause
hMissing/loose connection
hTripped circuit breaker
AC Indicator
Flashing
Problem Low AC voltage present
Possible
Cause
hLow AC voltage power source
hIncorrectly congured for
source voltage
Fault
Indicator
Problem Charger error
Possible
Cause
hIncorrectly connected battery
hIncorrectly connected power
source
hInternal short circuit
Disconnect power source prior to opening control box
or performing further troubleshooting/repairs. Ensure all
electrical connections are secure. Check connections for
correct polarity. Verify circuit breakers are not tripped.
Verify power source voltage is correct and matches BCU
transformer (if applicable) and circuit breaker settings.
Reconnect power and check for AC Indicator and Fault
Indicator lights for proper BCU operation.
CHARGER SOURCE VOLTAGE
WARNING
!
Electrical hazard: All electrical work must be done by qualified personnel
in accordance with national, state and local codes.
System labeling: HOTSTART recommends relabeling BCU if modified
from original factory shipped labeling to prevent connecting to incorrect
power source voltage.
1. Ensure your BCU model can accept the power source. BCU
models without transformers may accept 120, 208 or 240
volt power sources. Models with transformers may accept
460, 480, 575 or 600 volt power sources. CAUTION! Do
not attempt to congure BCU for a voltage source
that is not listed as an available power source for your
model. Contact HOTSTART for additional voltage
conguration options, as conversion may require
additional or replacement parts.
BCU MODELS WITHOUT TRANSFORMERS
BCU Model Primary Voltage Available Voltages (w/o parts)
120 V 208 V, 240 V
208 V 120 V, 240 V
240 V 120 V, 208 V
BCU MODELS WITH TRANSFORMERS
BCU Model Primary Voltage Available Voltages (w/o parts)
480 V 460 V, 575 V, 600 V
575 V 460 V, 480 V, 600 V
2. Disconnect BCU from power source. Open control box
lid. Locate circuit breaker CB1. Adjust CB1 setting to
amperage setting listed on following page. CAUTION! Do
not adjust CB2 amperage setting (if applicable).
3. Locate transformer T1 (if applicable). Disconnect and
reconnect transformer jumpers to terminals positions listed
on following page. Reference part drawings for specic
model information.
Ammeter
Displays scale of
output during
bulk charge
phase.
(BCU is not
congured for
bulk charging.)
Fault Indicator
Charger error.
AC Indicator
Solid
AC power is
present.
Flashing
Low AC voltage.
Bulk Charge Indicator
Bulk charge phase
complete (80%
charged); in
absorption phase.
Charge Completion
Solid
Charging complete
and maintenance
mode is active.
Flashing
Absorption phase
complete, in nishing
phase.
Figure 6. BCU charger interface.
Figure 7.
Adjusting CB1
amperage
(A) and
reconnecting
transformer
jumper (B).
