Kofloc 8700 MC, Instruction Manual

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MJ400306A1
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16. Troubleshooting and Precautions for Servicing
(1) Troubleshooting and corrective action
Symptom Possible Cause Check and Action
1. The sensor will not
output.
a. The power is not on. 1. Check to see if the power lamp is on.
b. Connection with the indicator is not
correct.
1. Reconnect. Check wire colors to see if wires are
connected correctly
c. Gas is not being supplied. 1. Check to see if the source pressure of the cylinder is
sufficient and the valve is open.
2. Check to see if the solenoid valve, 3-way valve, etc. in
the line are working properly.
3. Check the line filter for clog.
d. The outlet side piping of the mass flow
controller is blocked.
1. Check the solenoid valve, 3-way valve, air valve, etc.
e. The forced close signal has been input
to the mass flow controller.
1. Check to see if the valve forced close signal GND has
not been input to Pin No. 8
f. The power supply is faulty. 1. Disconnect the cable and check the power supply
voltage 24 VDC (
±
5% max.) with a tester. If no voltage
is present, replace the power supply.
g. The orifice is clogged. 1. The orifice needs to be overhauled and cleaned or
replaced. Please send it to KOFLOC.
h. The sensor tube is clogged. 1. If the tube is clogged, gas keeps flowing. Check it.
The sensor needs to be replaced. Please send it to
KOFLOC.
2. The output will not
become zero (power on 45
minutes or longer)
a. The control valve is leaking internally
or externally.
1. Disconnect the piping before the mass flow controller
to remove gas and check to see if the output will become
zero.
b. The command and external setter are
not connected correctly.
1. Check wiring of the command and external setter.
c. If the above wiring has no problem, the
sensor is faulty or the electronic circuit is
faulty.
1. The electronic circuit is faulty. Please send it to
KOFLOC.
D. The sensor is faulty or the electronic
circuit is faulty.
1. The zero point may be adjusted for reuse, but the flow
accuracy will be impaired.
Please send it to KOFLOC.
3. When gas is flowing,
the indicated flow rate is
not stable.
a. The supply pressure on the inlet side
of the mass flow controller is unstable
constantly.
1. Install a pressure regulator on the inlet side to make
the pressure constant.
b. The control valve is faulty. 1. Please send it to KOFLOC.
c. The indicator is faulty. 1. Replace the indicator.
d. The connector is not connected correctly. 1. Check to see if the connector has been fitted firmly.