Voltage Reduction Device (Vrd); Vrd Specification; Vrd Maintenance - Thermal Arc 185 AC Service Manual

9.01 VRD Specification:

Description
VRD Open Circuit Voltage
VRD Resistance
VRD Turn OFF Time

9.02 VRD Maintenance

Routine inspection and testing (power source):
An inspection of the power source, an insulation resistance
test and an earth resistance test shall be carried out.
A) For transportable equipment, at least once every 3
months; and
B) For fixed equipment, at least once every 12 months.
The owners of the equipment shall keep a suitable record
of the periodic tests.
A transportable power source is any
equipment that is not permanently connected
and fixed in the position in which it is operated.
May 22, 2006

VOLTAGE REDUCTION DEVICE (VRD)

15.3 to 19.8V
148 to 193 ohms
0.2 to 0.3 seconds
NOTE
ARCMASTER 185 ACDC 200 ACDC
SECTION 9:
Open circuit voltage between welding terminals
The required resistance between welding terminals
to turn ON the welding power
The time taken to turn OFF the welding power once
the welding current has stopped
In addition to the above tests and specifically in relation
to the VRD fitted to this machine, the following periodic
tests should also be conducted by an accredited Thermal
Arc service agent.
Description
VRD Open
Circuit Voltage
VRD Turn ON
Resistance
VRD Turn OFF
Time
If this equipment is used in a hazardous location or
environments with a high risk of electrocution then the
above tests should be carried out prior to entering this
location.
Notes
IEC 60974-1 Requirements
Less than 20V; at Vin=460V
Less than 200 ohms
Less than 0.3 seconds
Periodic Tests
9-1