Hitachi UTOPIA RAS-4HVRP2E Service Manual page 163

8 Electrical checks of main parts
Inverter
Protection function
Applicable
RAS-3HVRC2
model
Excessive high
Excessive low voltage at a voltage is lower than 194 V DC
or low voltage
Excessive high voltage at a voltage is higher than 400 V DC
for inverter
1 When the compressor's operating frequency reaches 15 to 18
Hz after the compressor starts, the effective value of running
current at each phase is 1.5A or less.
2 The wave height value of running current for the phase
Abnormality of
current sensor positioning is 5A or less before the compressor starts (at the
(0A detection)
end of the phase positioning).
Cause of Abnormality: Failure of Current Sensor (on Inverter
PCB),
Failure of IPM, Failure of Compressor, Disconnected Wiring
Rated
Rated current x
current
150%
x 150%
Rated
Rated current x
current
105%
x 105%
Short-circuit trip of arm *)
Overcurrent
protection for
Instantaneous overcurrent trip *)
inverter
Instantaneous overcurrent trip: it is detected when current valve is over rated current x 150%.
Electronic thermal trip: it is detected when current valve rated current x 105% for over 30 seconds or for over 3
minutes in total within 10 minutes.
NOTE
*) Internal protection IPM
Condition is maintained longer than 30 seconds or accumulated longer than 3 minutes during 10 minutes sampling
time.
IPM has four protection function for self-protection.
Protection
Short circuit in any of the "U", "V" or "W" terminals
of transistor
Running current reaches the maximum rated current.
module
Control voltage decreases abnormally.
Overload control as a current greater than rated current X105%.
Overload
control
Overload control release at a current smaller than rated current X 88%.
Fin
temperature The unit is stopped when the fin temperature is higher than 80ºC (for 3HP), 90ºC (for 4 to 6HP).
increase
Earth detection The unit is stopped when the compressor is earthing.
161 SMGB0136 rev.0 - 07/2021
RAS-(4-6)HVNC1E
Detecting current is more than
Detecting current is more than
150% of the rated current
150% of the rated current.
Time
RAS-(4-6)HNC1E
Excessive low voltage at a voltage is
lower than 350 V DC
Excessive high voltage at a voltage is
higher than 750 V DC
Stoppage at a current of compressor
smaller than 1.5A.
When the frequency is 15 to 18Hz after
starting. Cause of abnormality:
Failure of current sensor
Failure of IPM/DIP-IPM/ ISPM
Failure of compressor / fan motor
Disconnected wiring
8