20
MNL107-900-000D
SECTION 5
TROUBLE SHOOTING
5.1 TROUBLESHOOTING
In the event problems are encountered during the installation and operation of the inverter refer to
the chart below before assuming the inverter is at fault. If it is determined the fault is with the
inverter, contact Behlman Electronics for service information.
SYMPTOM
POSSIBLE CAUSE
ACTION
Low or no output status LED off.
AC output LED may be off.
Output overloaded
Check load current. Disconnect
load and recheck output voltage
using TRUE RMS meter.
Recycle power.
Erratic operation
Input voltage fluctuating
Monitor voltage at the DC input
terminals of the inverter. Make
sure DC is within specifications.
No AC input alarm
AC input LED off.
AC - Bypass fuse blown
Check fuse. Measure AC input
at rear panel.
Output distorted
High peak load current or non-
linear load.
Reduce loading if distortion
is objectionable. Check load
current waveform.
DC breaker repeatedly trips
DC polarity reversed or internal
fault in inverter.
Check polarity, if ok the unit
may have an internal fault.
Return for service.
SPECIAL CONSIDERATION FOR MOTORS
Loads that contain motors may present a special problem due to a mechanical load being
present.The start-up (a.k.a. Locked rotor current) for these devices may be much higher than
expected. These currents may also last from several cycle of the AC waveform to several
seconds. Motor start current “profiles” must be understood to prevent overloading the AC/DC
1200
5.2 MAINTENANCE
!
WARNING
Service of this device requires specialized equipment and trained personnel. There are no
internal user serviceable parts. Removing the covers will expose individuals to hazardous
voltages.
Refer service to qualified personnel only!
If the unit is to be supplied from batteries, the condition of the batteries will have a significant
effect on the operation of the unit. Poorly maintained batteries can cause the unit malfunction
when heavily loaded. If this device is to be used as part of a back-up power system a battery
maintenance schedule should be discussed with the battery manufacturer. Battery condition can
deteriorate quickly without proper maintenance. Behlman does not provide batteries for these
units. When performing battery maintenance, check and tighten all wire connections.
