Hitachi PSC-A64S - Troubleshooting

7 Gateways for building management systems
HARC-BX E
TCGB0106 rev.0 - 12/2014
688688
7.4.6 Troubleshooting
The following table shows the possible troubleshooting actions to be carried out in the event of unit malfunction.
Make sure that the power supply is disconnected before starting any check.
No. Phenomenon Check points Action
1
The HARC-BX
E does not start
up although the
power supply is
turned on.
(No indication in
the 7-segment
display).
Check that the electricity cable is connected. Connect the electricity cable.
Check that it supplies electricity.
Measure the power supply voltage. If the voltage meas-
urement exceeds the normal range of 100~240±10%[V],
the wiring systems and procedures should be inspected
and examined.
Check if the power supply is turned on (PWRs
ON).
If the pilot light is off there may be a fault in the internal
power supply. Contact your nearest service centre.
Check whether the screws on the power supply
are loose.
Tighten them.
Check if the LED (PWR or transmission display)
is on.
Check the transmission circuit of the air conditioning
systems with the self-check function. Then check if the
monobloc air conditioning transmission circuit is operat-
ing normally.
Check if the LED (LON or transmission display)
is on.
Check the upper transmission circuit with the self-check
function. Then check if the upper transmission circuit is
operating normally.
Check if the LED (LON or transmission display)
is ashing at regular intervals (from 1 to 2 sec.).
The ashing indicates that there could be a fault in the
internal power supply. Contact your nearest service
centre.
2
The HARC-BX E
does not identify
the air condition-
ing even though
the power supply
is on.
(“11” appears on
the 7-segment
display).
After the “00”
indication on
the 7-segment
screen with test
mode, the ac-
tual amount of air
conditioning units
does not match
with these ad-
dresses.
Check if the HARC-BX E (OP) DIP switches are
correctly congured.
The DIP switch must be congured again following the
installation and maintenance manual and operation
manual on how to congure the HARC-BX E DIP switch.
Check if the air conditioning system and ad-
dress are correctly congured.
The address should be congured again as indicated in
the installation and maintenance manual and the opera-
tion manual.
Check if the transmission cable to the air condi-
tioning units is disconnected.
Examine the cable connection.
Check if the transmission cable specied by the
manufacturer has been used to connect to the
air conditioning units.
Use a shielded cable or twisted and shielded pair cable
(0.75 mm
2
).
Check if the transmission cable connected to
the air conditioning is connected to the power
supply cable.
Leave a minimum space of 150 mm between cables.
Check if the termination resistance of the termi-
nal and the number of the transmission cable to
the air conditioning unit is correctly congured.
Only one termination resistance should only be cong-
ured on one system. (The resistance between cables is
approx. 150 Ω).
Check if the transmission circuit operates nor-
mally with the self-check function.
The termination resistance should be congured in rela-
tion to the air conditioning transmission cable.
Check if the air conditioning's power supply is
ON.
The air conditioning should be in the ON position.
Check if the transmission cable between the air
conditioning units is disconnected.
Examine the cable connection.
Check if the LED (H-L) of the transmission dis-
play is on.
Check the transmission circuit of the air conditioning
system with the self-check function. Then check if the air
conditioning transmission circuit is operating normally.
Check if the LED (H-L) of the transmission dis-
play is off.
Check the transmission circuit of the air conditioning
system with the self-check function. Then check if the air
conditioning transmission circuit is operating normally.