Hitachi Set Free mini-HNRQ1 Series, Service Manual

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141
MAINTENANCE
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Protective Function
(i). Excessive High or Low Voltage for Inverter
(a) Level of Detection
When the voltage of direct current is greater than 450V, an abnormality is detected.
When the voltage of direct current is smaller than 190V, an abnormality is detected.
(b) Function
When an abnormality is detected, the inverter compressor is stopped and the cause code of inverter
stoppage is communicated to outdoor unit PCB.
(c) Cancellation of Protection Function
When the wired controller is off or main power supply is cut off.
(ii). Overcurrent Protection for Inverter
(a) Level of Detection
When the current detected reaches 85% of the demagnetization current, overcurrent is detected.
(Instantaneous Overcurrent)
When the current detected exceeds the rated current continuously for 10 seconds, overcurrent is
detected.
(b) Function
When an abnormality is detected, the inverter compressor is stopped and the cause code of inverter
stoppage is communicated to main control.
(c) Cancellation of Protection Function
When the wired controller is off or main power supply is cut off.
(iii). Protection of IPM of Inverter
(a) Level of Detection
When some of the output terminals between “U” and “V”, “V” and “W”, “W” and “U” of DIPIPM of
inverter PCB are short-circuited, an abnormality is detected.
When the running current of DIPIPM of inverter PCB reaches the maximum rated current, an
abnormality is detected.
When the control voltage of DIPIPM of inverter PCB abnormally decreases, an abnormality is detected.
(b) Function
When an abnormality is detected, the inverter compressor is stopped and the cause code of inverter
stoppage is communicated to outdoor unit PCB.
(c) Cancellation of Protection Function
When the wired controller is off or main power supply is cut off.
(iv). Fin Temperature Increase
(a) Level of Detection
When the temperature of internal thermistor exceeds more than 95°C, an abnormality is detected.
(b) Function
When an abnormality is detected, the inverter compressor is stopped and the cause code of inverter
stoppage is communicated to main control.
(c) Cancellation of Protection Function
When the wired controller is off or main power supply is cut off.
(v). Overload Protection Control