Figure 1 provides minimal information for selection of line conductors, overcurrent protection, and the
equipment grounding conductor. This information is from the National Electrical Code NFPA 70-1981 Edi-
tion. Install this equipment per the latest edition, available from the National Fire Protection Association,
470 Atlantic Avenue, Boston, MA 02210.
Connect the three-phase line leads to terminals L1, L2, and L3 on the line contactor (top end) located on
the rear of the lifting baffle inside the power supply cabinet.
NOTE: After connecting the input cables, it is recommended that Hobart #904021 urethane coating be
sprayed on the connections at the line contactor to protect these connections from corrosion, fungus,
and contamination. Spraying these connections will also reduce the potential for arcing from dirt and
condensation.
Copper Copper
Rated Line Wire Size * Grounding
Line Amps Conductor
Volts In Conduit Flexible Cable Min. Size
208 86 No. 3 No. 3 No. 3
230 78 No. 4 No. 4 No. 4
460 39 No. 8 No. 8 No. 8
220 82 No. 4 No. 4 No. 4
380 47 No. 8 No. 8 No. 8
230 79 No. 4 No. 4 No. 4
460 39 No. 8 No. 8 No. 8
575 32 No. 8 No. 8 No. 8
Recommended Wire Size Table
Figure 1
* Conductor sizes listed are for 30 feet or less of each conductor in conduit and for conductors having
90C insulation, such as type FEP, FEPB, RHH, and THHN. For conductors having other insulation, or for
conductors longer than 30 feet, consult Hobart Brothers Company as to size required.
D. Grounding
The frame of this ground power unit should be grounded for personnel safety, and to assure operation of
the overcurrent protection. The grounding method, and the equipment grounding conductor size and type
shall conform to local and national codes. For the National Electrical Code, the equipment grounding con-
ductor shall be green, green with a yellow stripe, or bare. If flexible power cable is used, use a cable as-
sembly which includes the equipment grounding conductor. If metallic armored cable or conduit is used,
the metal sheathing or conduit must be effectively grounded per local and national codes.
Rubber-tire mounted equipment shall be grounded to conform to local national codes. The grounding as-
sists in providing protection against line voltage electrical shock and static shock. The grounding serves to
discharge the static electric charge which tends to build up on rubber-tire mounted equipment. This static
charge can cause painful shock and lead to the erroneous conclusion that an electrical fault exists in the
equipment. An ungrounded cabinet can be at a lethal potential if a component fails electrically to the case.
OM-2010
1-2 April 10/89 Revised
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