A-4

INSTALLATION

A-4

The high frequency generator, being similar to a radio transmitter, may cause radio, TV and electronic equip- ment interference problems. These problems may be the result of radiated interference. Proper grounding methods can reduce or eliminate radiated interfer- ence.

Radiated interference can develop in the following four ways:

1.Direct interference radiated from the welder.

2.Direct interference radiated from the welding leads.

3.Direct interference radiated from feedback into the power lines.

4.Interference from re-radiation of “pickup” by ungrounded metallic objects.

Keeping these contributing factors in mind, installing equipment per the following instructions should mini- mize problems.

1.Keep the welder power supply lines as short as possible. Input leads within 50 feet (15.2m) of the welder should be enclosed in rigid metallic conduit or equivalent shielding. There should be good elec- trical contact between this conduit and the welder case ground. Both ends of the conduit should be connected to a driven ground and the entire length should be continuous.

2.Keep the work and electrode leads as short as pos- sible and as close together as possible. Lengths should not exceed 25 ft (7.6m). Tape the leads together when practical.

3.Be sure the torch and work cable rubber coverings are free of cuts and cracks that allow high frequen- cy leakage.

4.Keep the torch in good repair and all connections tight to reduce high frequency leakage.

5.The work piece must be connected to an earth ground close to the work clamp, using one of the following methods:

a)A metal underground water pipe in direct contact with the earth for ten feet or more.

b)A 3/4” (19mm) galvanized pipe or a 5/8” (16mm)solid galvanized iron, steel or copper rod driven at least eight feet into the ground.

The ground should be securely made and the ground- ing cable should be as short as possible using cable of the same size as the work cable, or larger. Grounding to the building frame electrical conduit or along pipe system can result in re-radiation, effectively making these members radiating antennas.

6.Keep cover and all screws securely in place.

7.Electrical conductors within 50 ft (15.2m) of the welder should be enclosed in grounded rigid metal- lic conduit or equivalent shielding, wherever possi- ble. Flexible metallic conduit is generally not suit- able.

8.When the welder is enclosed in a metal building,the metal building should be connected to several good earth driven electrical grounds (as in 5 (b) above) around the periphery of the building.

Failure to observe these recommended installation procedures can cause radio or TV and electronic equipment interference problems and result in unsat- isfactory welding performance resulting from lost high frequency power.

INPUT CONNECTIONS

Be sure the voltage, phase, and frequency of the input power is as specified on the rating plate, located on the rear of the machine.

208/230 volt models have a NEMA 6-50P plug attached to the #8-3 input power cord and a NEMA 6 - 50R receptacle is included with the Ready-Pak mod- els. Other voltage models have an input power cord but no plug or receptacle.

Have a qualified electrician provide input power sup- ply to the receptacle or cord in accordance with all local and national electrical codes. Use a single phase line or one phase of a two or three phase line. Choose an input and grounding wire size according to local or national codes. Refer to the Technical Specifications page at the beginning of this section. Fuse the input circuit with the recommended super lag fuses or delay type1 circuit breakers. Using fuses or circuit breakers smaller than recommended may result in “nuisance” shut-offs from welder inrush currents even if not welding at high currents.

1Also called “inverse time” or “thermal/magnetic” circuit breakers; circuit breakers which have a delay in tripping action that decreases as the magnitude of the current increases.

PRECISION TIG 185

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Lincoln Electric TIG 185 manual Input Connections