172-65188M-08 (
M-COS 3,16,21
Pressure Reducing Valve) 24 Jun 2015
28
<Controller>
Replacing the Fuse
If the power ON LED fails to light even after the power switch is turned ON, check
whether the fuse is blown.
Controller
(Rear View)
Fuse
Rear Cover
Circuit Board
Set screws to be
removed
Figure 5.1
Figure 5.2
CAUTION: Be sure the main power is switched OFF before checking the fuse.
1. Remove both pair of set screws on both sides of the controller (Figure 5.1).
2. The cartridge fuse mounted inside is exposed by removing the rear cover (Figure
5.2).
3. Using a pair of electrician’s pliers or similar implement, pry out the fuse and
check. If blown, replace it with a new fuse.
Fuse rating: 250V, 2A
Type: Cartridge type, dia. 5.2
×
20 mm
Inspecting and Adjusting the Pressure Indication
Equipment used for adjustment
–
DC current
generator
1. An electric current of 4mA DC is fed from the
DC current generator to the pressure signal
input terminals on the controller (terminal
numbers: 8 (+ side) and 9 (- side)).
2. Check to see that the digital pressure
indication then reads -002 – +002 (
±
0.1%FS).
3. If the pressure reading indicated falls outside
this range adjust with the zero adjustment
screw shown in Fig. 5.3 until the pressure
indicated comes into the range.
Zero Adjustment Screw
Span Adjustment Screw
Adjustment screws
for
pressure indication
Figure 5.3
4. Next, change the input signal to 16mA and check to see that the valve indicated
reads 1498 – 1502 (374 – 376 for 500 kPa).
5. If the value indicated falls outside the range, adjust with the span (gain)
adjustment screw shown in Fig. 5.3 until the correct reading is obtained.
NOTE: Except for the above-mentioned adjustments, the controller requires no
further maintenance. If any abnormality is noted, contact our sales
representatives.
