Electrical Connections, Operating Instructions

Electrical Connections

All electrical connections must be made by a qualified electrician! Failure to comply may cause serious injury!

General Electrical Cautions

This machine must be grounded in accordance with the National Electrical Code and local codes and ordinances. This work should be done by a qualified electrician. The machine must be grounded to protect the user from electrical shock.

Wire Sizes

For circuits which are far away from the electrical service box, the wire size must be increased in order to deliver ample voltage to the motor. To minimize power losses and to prevent motor overheating and burnout, the use of wire sizes for branch circuits or electrical extension cords according to the following table is recommended:

Operating Instructions

Operating Controls

The lubrication system is a manually operated, one- shot system requiring operator intervention. The operator must lower the one-shot lever to lubricate the machine ways and ball screws. The one-shot lubrication system reservoir is located on the left side of the machine.

The position of the milling machine mill head can be set up to accommodate the work piece being machined. The mill head can be set up for angles to the left or right and for fore and aft angles. The mill head can also be rotated on its turret. The ram can be moved back and forth to reach work piece locations at the fore and aft extremes of worktable travel. Refer to the Adjustments section.

Motor Switch

The Motor Switch is on the upper left-hand side of the mill head (Figure 5). The switch has three positions: FWD (forward), STOP, and REV (reverse).

Conductor Length

0 – 50 Ft.

50 – 100 Ft.

Over 100 Ft.

AWG Number

230/460 Volt Lines	120 Volt Lines
No. 14	No. 14
No. 14	No. 12
No. 12	No. 8
Figure 4

Setting the switch to FWD will provide clockwise spindle rotation. Use FWD for normal, right-hand tooling.

FWD (clockwise) operation occurs only when the gearbox is in the low speed position. When the gearbox is in high-speed position, the motor switch must be in the REV position to provide right-hand or

Confirm that power at the site matches power requirements of the mill before connecting to the power source.

The JTM-4VS has been pre-wired for 230 volt operation. To change from 230V to the other voltage offered, remove the junction box cover on the motor and change the wires according to the diagram found on the inside of the cover.

Before connecting to the power source, make sure that the switch is in the off position.

The mill must be properly grounded.

Check for proper spindle rotation in the high-speed range. The spindle should rotate clockwise when viewed from the top of the machine. If the spindle rotates counter-clockwise, disconnect from power and switch two of the three power leads.

Lubrication

Do not operate the mill before lubricating the machine fully. Failure to comply may cause damage to the machine.

Refer to the Maintenance/Lubrication section and make sure the machine has been fully lubricated before operating.

clockwise rotation. Refer to Figure 6 for a chart of required switch positions.

The motor switch controls a three-phase motor. The motor can be switched from FWD to REV and back with the motor running, and will reverse direction when the switch setting is changed. At higher speeds, this may put strain on the timing belt but there will be no damage to the motor or gear mechanism.

Figure 5