Hitachi UTOPIA RAS-4HVRP2E - Page 94

5 Control System
Protection control
SMGB0136 rev.0 - 07/2021
92
Related protection control
a. Pressure ratio decrease protection control (P1).
b. Discharge pressure increase protection control (P2).
c. Inverter overcurrent protection control (P3).
d. Inverter n temperature increase protection control (P4).
e. Discharge temperature increase protection control (P5).
Example of discharge temperature increase protection control for
RAS-(4-6)H(V)(R/N)(C/P)2E:
92
110
90
95
85
90
92
97
87
105
A Normal operation
B
Not allowing frequency increases (only frequency decreases
are allowed) Forced decrease in frequency (1.0 Hz/s)
C Forced decrease in frequency (0.25 Hz/s)
D Abnormal stoppage (cause of stoppage d1-15)
(1) For 5 seconds
(2) For 10 minutes
N Normal
D Degeneration
Td Discharge gas temperature sensor detected value