Tweco 250i Transmig Inverter - Manual (Page 82)

TRANSMIG 250i PROBLEMS/SERVICE
PROBLEMS AND ROUTINE SERVICE 5-4 Manual 0-5187
C. Earthing/Grounding
The resistance shall not exceed 1Ω between any metal of a power source where such metal is required to be
earthed, and -
1. The earth terminal of a fixed power source; or
2. The earth terminal of the associated plug of a transportable power source
Note that due to the dangers of stray output currents damaging fixed wiring, the integrity of fixed wiring sup-
plying CIGWELD welding power sources should be inspected by a licensed electrical worker in accordance
with the requirements below -
1. For outlets/wiring and associated accessories supplying transportable equipment - at least once every
3 months; and
2. For outlets/wiring and associated accessories supplying fixed equipment - at least once every 12 months.
D. Voltage Reduction Device (VRD)
Units fitted with VRD's, shall have the periodic tests outlined in Table 5-3 below conducted by an accredited
CIGWELD service provider. Testing shall be conducted at intervals as outlined below -
1. For transportable equipment, at least once every 3 months; and
2. For fixed equipment, at least once every 12 months.
Description Required Parameters
VRD Open Circuit Voltage Less than 35V; at nominal input voltage
VRD Turn ON Resistance Less than 200 ohms
VRD Turn OFF Time Less than 0.3 seconds
Table 5-3: VRD Periodic Tests
E. General Maintenance Checks
Welding equipment should be regularly checked by an accredited CIGWELD Service Provider to ensure that:
1. Flexible cord is of the multi-core tough rubber or plastic sheathed type of adequate rating, correctly
connected and in good condition.
2. Welding terminals are in suitable condition and are shrouded to prevent inadvertent contact or short
circuit.
3. The Welding System is clean internally, especially from metal filing, slag, and loose material.
F. Accessories
Accessory equipment, including output leads, electrode holders, torches, wire feeders and the like shall be
inspected at least monthly by a competent person to ensure that the equipment is in a safe and serviceable
condition. All unsafe accessories shall not be used.
G. Repairs
If any parts are damaged for any reason, it is recommended that replacement be performed by an accredited
CIGWELD Service Provider.