Getting people to use them can be a
problem, having to book them out of store etc?
A.
The new products can now be fitted internally.
Q.
The current VRD’s on the market
are larger and heavier than the inverter?
A.
There is now VRD technology that is reduced to the size
of two matchboxes.
Q.
How do we know the VRD is operational?
A.
A test unit is available that can be used to test the correct
operation of the V.R.D.
Q.
What about a colour blind operator,
how can they differentiate, as red and green merge?
A.
All Safetac VRD units have flashing Red lights to indicate
Danger the electrode is live and constant Green to indicate
the output voltage is reduced and the electrode is safe to
change.
Q.
I was told i cannot fit an internal
VRD to my Inverter welder,is there another option?
A.
If the site allows you can use an external DM1(200 Amp)
or DM2 (400 Amp) Deadman isolation switch .
Q.
How can we stop operators from bypassing
the system?
A.
If you have the new VRD workshop fitted internally, it becomes
part of the normal operating system.
Q.
Will it effect the equipment?
A.
No, the inverter model will not effect the equipment manufacturers
duty cycle. The engine drive model has a duty cycle of 400
Amps @ 100%. This can be upgraded to 600 amps adding an extra
contactor.
Q.
If the site allows can I use a trigger
or remote switch on the handpiece (electrode holder) to activate
the welder.
A.
Yes. This method will function and offer an improved degree
of safety over no protection at all but there is still a possibility
of the operator coming into contact with full OCV 110 Volts
during the weld iniation cycle. This is because of the welder
design allows full OCV to be present when the trigger is pressed
and welder is in an unloaded condition. With a VRD the welder
is turned only in a loaded condition causing the output voltage
to be around 20 to 40 volts rather than 110 or full OCV .
Most welding shocks are caused by contact with the electrode
or becoming the path for a poor work return circuit during
the weld iniation or rod changing cycle. With a trigger operated
activation either intentional or not it is possible for the
operator to come into contact for longer than 2 sec with full
OCV during the iniation stage. Also with a trigger operated
welder if the work return circuit is incomplete and the operator
presses the trigger to begin welding and at the same time
is in contact with the work return circuit they would receive
a full ocv shock. With a VRD welder the welder is not turned
to full output until there is a metal to metal contact of
less than 200 ohms which also pulls the output of the welding
machine to a voltage of less than ½ of the normall
ocv Also with a VRD if the work leads return circuit is incomplete
(Bad Earth) the welder will not activate as the resistance
is above 200 ohms offering a high degree of protection to
the operator.
Q.
Cables and leads to a switch operation
mean more to go wrong and may carry a voltage !
A.
The only cables required for this VRD operation are your
normal handpiece and work lead.
Q.
Why is it necessary to reverse the leads
when I reverse my polarity?
A.
You no longer have to do this for the V.R.D. although you
still need to reverse the welding leads.
Q.
We need something compact and simple?
A.
The new range of VRD units available meets both of these
requirements.
Q.
If I require a external VRD as opposed
to a internal unit it has to be robust and the casing has
to withstand corrosion in harsh environments?
A.
You can get the external model which comes in 304L or 316L
stainless steel.
Q.
What about striking the ARC on low hydrogen
electrodes?
A.
This V.R.D. has a very quick response time
Q.
Do the SafeTac VRD units comply with
Australian Standards?
A.
Yes the equipment has been tested by Western Power, Metering
Division N.A.T.A.
Lab Accreditation No 47 for compliance to Australian Standards
Ruling No 3195 Section 17,AS 1674.2 2003 WTIA Tech note 22-02
Q.
Do you have test reports on the range
of SafeTac VRD units?
A.
Yes a full N.A.T.A. test report is available upon request.
Q.
What about tacking?
A.
All SafeTac VRD units have a .3 second post weld delay to
enable tacking operations,this is the maximum time allowed
under Australian Standards.
