4 welding and earth cables, 2 pilot lamps, 3 operation of cooling fan – Kemppi KMS 400 MVU User Manual

Page 9

Sizes of the mains cables and fuse ratings for the machine at 100 % duty cycle are specified in

the table below:

Rated voltage

Fuses, slow-blow

Connection cable *) mm²

400 V 3~

35 A

H07RN-F 4G10 (10 mm²)

230 V 3~

50 A

H07RN-F 4G10 (10 mm²)

*) In cables of S type there is a protective grounding conductor coloured green-yellow.

2.4 Welding and earth cables

Recommended copper cables with cross-sectional area are as follows:
FastMig KMS 400 MVU

70 ... 90 mm²

In enclosed table are shown typical load capacities of rubber insulated copper cables, when

ambient temperature is 25º C and lead temperature is 85º C.

Cable

Duty cycle ED

Voltage loss / 10 m

100 %

60 %

30 %

50 mm²

285 A

370 A

520 A

0,35 V / 100 A

70 mm²

355 A

460 A

650 A

0,25 V / 100 A

95 mm²

430 A

560 A

790 A

0,18 V / 100 A

Do not overload welding cables due to voltage losses and heating.
Fasten the earth clamp of the return current cable carefully, preferably direct onto the piece to

be welded. The contact surface of the earth clamp should always be as large as possible.
Clean the fastening surface from paint and rust.

OperatiOn COntrOl sWitChes anD pOtentiOmeters

3.1 main switch i/O

When you turn the switch into I-position, pilot lamp H11 on the front face is illuminated and

the machine is ready for use.

NOTE!

Always turn the machine on and off with the mains switch, never use the mains plugs as a

switch.

3.2 pilot lamps

The pilot lamps of the machine report the electric operation:
The green pilot lamp H11 when lit indicates that the machine is on and ready for use and it is

connected to the mains supply with the main switch in the I-position.
H12 indicates when lit that the thermal protection of the machine has been activated due to

over heating. The cooling fan will continue to run and cool the machine down and when the

lamp is off the machine is ready to weld.

3.3 Operation of cooling fan

In FastMig power sources there are two simultaneously operating fans.

• The fan is started for a moment when main switch is placed into position I.

• The fan will start during welding as the machine heats up and it will run for 1 to 10

minutes after the welding has stopped.