Miller Electric NT 450, NT 500 Connecting Input Power, = GND/PE Earth Ground, Tools Needed 1/2

4-14. Connecting Input Power

9		= GND/PE Earth Ground
		8
		11
		10
			2
4
7
		1
		IMPORTANT
		6	3
			Input Contactor
		L1 (U)
	7	L2 (V)
4		L3 (W)
5	4
		3
		= GND/ PE Earth Ground

Tools Needed: 1/2 in

3/8 in

! Installation must meet all National and Local Codes − have only quali- fied persons make this installation.

! Disconnect and lockout/tagout in- put power before connecting input conductors from unit.

! Make input power connections to

the welding power source first.

! Always connect green or green/yel- low conductor to supply grounding terminal first, and never to a line ter- minal.

See rating label on unit and check input volt- age available at site.

1Input Power Conductors (Customer Supplied Cord)

Select size and length of conductors using Section 4-12. Conductors must comply with national, state, and local electrical codes. If applicable, use lugs of proper amperage capacity and correct hole size.

Welding Power Source Input Power Connections

2 Strain Relief

Route conductors (cord) through strain re- lief and tighten screws.

3Machine Grounding Terminal

4Green Or Green/Yellow Grounding Conductor

5Reed Switch (Ground Current Sensor) (Optional)

Connect green or green/yellow grounding conductor to welding power source ground- ing terminal first. If unit is equipped with op- tional ground current sensor, route ground- ing conductor through reed switch two times and connect to grounding terminal.

6Welding Power Source Line Terminals

7Input Conductors L1 (U), L2 (V) And L3 (W)

Connect input conductors L1 (U), L2 (V) and L3 (W) to welding power source line ter- minals.

Close and secure access door on welding power source.

Disconnect Device Input Power Connec- tions

8Disconnect Device (switch shown in OFF position)

9Disconnect Device (Supply) Grounding Terminal

Connect green or green/yellow grounding conductor to disconnect device grounding terminal first.

10 Disconnect Device Line Terminals

Connect input conductors L1 (U), L2 (V) And L3 (W) to disconnect device line terminals.

11 Overcurrent Protection

Select type and size of overcurrent protec- tion using Section 4-12(fused disconnect switch shown).

Close and secure door on line disconnect device. Remove lockout/tagout device, and place switch in the On position.

800 103-C / Ref. 801 116-A

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