Kemppi KM 300 - Manual (Page 8)

EN
2.3 Connection to mains
FastMig KM power sources are connected to the 400-V three-phase network using the mains
cable supplied with the machine.
The machine is equipped with a five-metre mains cable that does not have a plug. Before use,
check the mains cable and install a mains plug. If the cable does not comply with the local
electrical regulations, replace it with a compliant cable. See ’Technical specifications’.
NOTE! The mains cable or plug may be installed or replaced by only an electrical contractor or
installer authorised to perform such operations.
Replacement of the mains cable
1. Unscrew the mounting screws on the top and sides of the machine, and remove the case
by lifting it.
2. Disconnect the phase leads from connectors L1, L2, and L3, and disconnect the
protective earth lead.
3. Pass the cable to the machine through the inlet ring at the rear of the machine, and
secure the cable with a cable clamp.
4. Connect the cable’s phase leads to connectors L1, L2, and L3.
5. Connect the yellow-green protective earth lead to its connector .
NOTE! Do not connect the zero lead if you are using a five-lead cable.
The table below lists the fuse sizes for 100% load in a 400-V three-phase network with
4 x 10-mm² cable for different power source models.
Model Fuse
KM 300 20 A delayed
KM 400 25 A delayed
KM 500 35 A delayed
2.4 Welding and earthing cables
The device has a welding cable connection both in the front and in the rear. The positions of
the welding and earthing cable connections are shown earlier in section ‘Introduction’.
The welding cable type to be used is rubber-insulated copper cable. The recommended cross-
sections of the cables for different power source models are as follows:
Model Cross-section
KM 300 50 – 70 mm²
KM 400 70 – 90 mm²
KM 500 70 – 90 mm²
The table below shows the typical load capacities of the cables when the ambient
temperature is 25 °C and the lead temperature is 85 °C.
Cable Duty cycle (ED) Voltage loss / 10 m
100 % 60 % 35 % 20 %
50 mm² 285 A 316 A 371 A 458 A 0,35 V / 100 A
70 mm² 355 A 403 A 482 A 602 A 0,25 V / 100 A
95 mm² 430 A 498 A 606 A 765 A 0,18 V / 100 A
120 mm² 500 A 587 A 721 A 917 A 0,21 V / 100 A
NOTE! Do not overload the welding cables, as an overload may cause voltage loss and
overheating.
Connect the earth clamp directly to the work piece in such a way as to maximise the contact
surface of the clamp. The point of connection must be unpainted and free of corrosion.
FastMig KM 300, 400, 500
6