TECHNICAL
BULLETIN
Date: 01-11-08
Product: A2281 Feeder on Fabricator 281 By: Jorge Santana
Subject: ON/OFF switch
7977847PKD
Summary: Green indicator going out
THERMAL ARC TECHNICAL SUPPORT
Phone: 1-800-462-2782
Fax: 1-603-298-7402
www.thermadyne.com
Form 0004
82 Benning Street
West Lebanon, NH 03784
1-603-298-5711
Fax: 1-800-221-4401
“Exceeding Customer Expectations Through Performance Excellence"
Valued Thermadyne Service Provider,
It has come to our attention that in some cases the Green Light (LED) in the ON/OFF switch of the
A2281 Feeder may go out.
The reason of this situation is that the LED did not have a reverse diode. On the negative half cycle of
the AC waveform, the LED could see reverse voltages higher than its maximum PIV (Peak Inverse Voltage).
With the addition of the reverse diode, the maximum PIV will be limited to the forward voltage drop
of the diode.
Nevertheless this situation WILL NOT
interfere nor affect with the functionality of the equipment.
All switches going forward will have the correct diode and resistor to prevent lamp failure.
Any new stock you receive from Thermal Arc on the p/n
7977847PKD will be to the latest spec.
Please do not hesitate to contact us if you have any questions.
For More information Contact:
Green LED
Reverse Diode
Resistor
Reverse Diode & Resistor installed
“inside” the 7977847PKD switch.
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