Hitachi RWM-(H)FSN3E, Service Manual

Page: 236 / 424

9 Electrical checks of
the main parts
SMGB0070 rev. 1 - 08/2011
226
4 Protection of IPM/DIP-IPM/ISPM
a. Level of detection
When some of the output terminals between “U” and “V”, “V” and “W”, “W” and “U” of IPM/dip IPM/ISPM are short-
circuited, an abnormality is detected.
When the running current of IPM/DIP-IPM/ISPM reaches (maximum rated current x 105%), an abnormality is de-
tected.
When an internal temperature is measured by internal thermistor of IPM, an abnormality is detected.
When the control voltage of IPM/DIP-IPM/ISPM decreases, an abnormality is detected.
b. Function
When abnormalities are detected, the inverter compressor is stopped and the signal code of stoppage cause is
transmitted to PCB1.
c.
Cancellation of protection function
Transmission for signal code of stoppage cause is canceled when a stopping order is issued or main power sour-
ce is cut off.
5 Fin temperature increase
a. Level of detection
When the temperature of internal thermistor exceeds more than 100 ºC, an abnormality is detected.
b. Function
When abnormalities are detected, the inverter compressor is stopped and the signal code of stoppage cause is
transmitted to PCB1.
c. Cancellation of protection function
Transmission for signal code of stoppage cause is canceled when a stopping order is issued or main power sour-
ce is cut off.
6
Earth detection
a.
Level of detection
When the starting current of the compressor reaches 80% of the overcurrent protection value, an abnormality is
detected.
b. Function
When abnormalities are detected, the inverter compressor is stopped and the signal code of stoppage cause is
transmitted to PCB1.
c. Cancellation of protection function
Transmission for signal code of stoppage cause is canceled when a stopping order is issued or main power sour-
ce is cut off.
9.1.4 Overload control
a. Level of detection
When the output current exceeds 105% of the maximum output current, an abnormality is detected.
b. Function
An overload signal is issued when output current exceeds 105% of the maximum output current, and the frequen-
cy decreases.
For 10 seconds after the output current decreases lower than 88% of the rated current, the operation is performed
with the compressor frequency limited to the upper level frequency when the output current decreases lower than
88% of the rated one.
However, if the frequency order is smaller than the maximum value, the operation is performed according to the
order.
c. Cancellation of protection function
After the operation described in the above item b. is performed for 10 seconds, this control is canceled.