YOKOGAWA PUS400G, Руководство пользователя

Страница: 23 / 31

< 4. Inspection and Maintenance >
4-2
IM 19C1B3-01E
4.2 Inspection When In-Action Pilot Lamp is OFF
The in-action pilot lamp may be kept OFF by erroneous operation (e.g. forgetting to turn ON the power
switch), or some trouble, such as anomalies in the wiring (disconnection and short circuit) and faults in
the equipment.
If the cause is such trouble, cope with it referring to Chapter 5.
4.2.1 Cause of Pilot Lamp Going Out
The following are suspected to be the cause of the in-action pilot lamp going out:
• Any of the fuses has burnt out.
The ultrasonic oscillator has two fuses, 1A and 2A, in the power receiving circuit and a 2A fuse in
the power circuit for the ultrasonic vibrator.
Turn OFF the power switch and check whether any of the fuses has burnt out. Refer to
Subsection 4.2.2 for details.
• The power cable for ultrasonic vibrator is disconnected or short-circuited.
The in-action pilot lamp goes out for the same reason as the case where the ultrasonic vibrator is
not immersed in fluid.
First, check to see that the cable is connected to the terminals on the ultrasonic oscillator with
reliability. Next, check the cable for any disconnection or short circuit using a tester or the like.
If the cable turns out to be faulty, cope with it in the instructions described in Subsection 5.2.1.
• There is a problem in the ultrasonic vibrator.
If the pilot lamp going out is caused by neither of the two above-mentioned problems, the cause
is often trouble in the ultrasonic vibrator.
Check the surface of the fluid-contacting area of the ultrasonic vibrator for any pit due to
corrosion. Referring to the user’s manual for the pH meter, examine the power supply circuit for
the ultrasonic vibrator in the holder.
If the cause of the in-action pilot lamp going out cannot be identified even after checking all the
above-mentioned items, contact YOKOGAWA.
4.2.2 Replacing Procedure for Fuse
(Check to see that the power switch is OFF before proceeding with the procedure.)
Using a flatblade screwdriver, remove the 1A fuse from the central one of the three fuse holders. If the
fuse had burnt out, install the attached 1A fuse, and turn ON the power switch to actuate the ultrasonic
oscillator.
If the fuse has not burnt out, install it as it was. Then check the right-hand adjacent 2A fuse (in the
power receiving circuit) and the left-hand adjacent 2A fuse (in the power circuit for the ultrasonic
vibrator), similarly.