Tweco 160 S Arcmaster - Manual (Page 41)

ARCMASTER ® 160 S
March 31, 2006 11-1
SECTION 11:
VOLTAGE REDUCTION DEVICE (VRD)
11.01 VRD Specifi cation
Description ArcMaster 160 S Notes
VRD Open Circuit Voltage 15.3 to 19.8V Open circuit voltage between welding terminals
VRD Resistance 148 to 193 ohms
The required resistance between welding
terminals to turn ON the welding power
VRD Turn OFF Time 0.2 to 0.3 seconds
The time taken to turn OFF the welding power
once the welding current has stopped
11.02 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 fi xed equipment, at least once every 12 months.
The owners of the equipment shall keep a suitable record of the periodic tests.
NOTE
A transportable power source is any equipment that is not permanently connected and fi xed in the position in
which it is operated.
In addition to the above tests and specifi cally in relation to the VRD fi tted to this machine, the following periodic tests should
also be conducted by an accredited Thermal Arc service agent.
Description IEC 60974-1 Requirements
VRD Open Circuit Voltage Less than 20V; at Vin=115V or 230V
VRD Turn ON Resistance Less than 200 ohms
VRD Turn OFF Time Less than 0.3 seconds
If this equipment is used in a location or environment with a high risk of electrocution then the above tests should be carried
out prior to entering this location.