Tweco 400i Transmig - Manual (Page 54)

TRANSMIG 400 i
6-14 July 18, 2008
6.10 Voltage Reduction Device (VRD)
1. VRD Specification:
Description Transtig 400 i 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
2. 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.
NOTE
A transportable power source is any equipment that is not permanently connected and fixed in the
position in which it is operated.
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 Cigweld service agent.
Description Required Parameters
VRD Open Circuit
Voltage
Less than 20V; at Vin=415V
VRD Turn ON
Resistance
Less than 200 ohms
VRD Turn OFF
Time
Less than 0.3 seconds
Periodic Tests
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.