Adjusting Pc Board; Adjusting Zero/Span Of Pump Pc Board (P/N 852-6010) - Hitachi L-8900 Service Manual

4.6 ADJUSTING PC BOARD

4.6.1 Adjusting ZERO/SPAN of PUMP PC Board (P/N 852-6010)

Items to be prepared;
UI pad for adjustment (P/N:852-8501)
Pressure gauge (for reference)
1. Connect UI pad to PUMP PC board.
2. Connect Pressure gauge (for reference) to the outlet of Drain
valve assembly.
3. ZERO adjustment
Open Drain valve, make UI pad LCD display 0, adjust VR1 so
that LCD pressure display will be within 0
4. SPAN adjustment
Pump liquid so that Pressure gauge shows 18.6 - 19.6 MPa
(190 -200 kgf/cm
Pressure display will be within (Actually measured pressure
value) 0.1 MPa.
5. Check ZERO/SPAN adjustment again, repeat 3, 4 above so
that Zero adjustment will be within 0
adjustment will be within (Actually measured pressure value)
0.1 MPa.
If Pressure Gauge cannot be prepared
Items to be prepared;
UI pad for adjustment (P/N: 852-8501)
Load resistance coil etc. corresponding to 18.6 - 19.6 MPa (190 -
2
200 kgf/cm ).
1. Connect a load to the outlet of Drain valve assembly of PUMP
side for which ZERO/SPAN adjustment is unnecessary.
2. Connect the outlet of Drain valve assembly of PUMP side for
which ZERO/SPAN adjustment is necessary and the inlet of
Drain valve assembly of PUMP side for which ZERO/SPAN
adjustment is unnecessary.
3. Connect UI pad to PUMP PC board to be replaced.
4. ZERO adjustment
Open Drain valve, make UI pad LCD display 0, adjust VR1 so
that LCD pressure display will be within 0
4 - 28
2
), keep the conditions, adjust VR2 so that
0.1 MPa.
0.1 MPa, SPAN
0.1 MPa.