Model 6210 Maintenance Manual

Section 7.Component Procedures

Electrical Components DC Motors, General

DC Motors, General

NOTE: For replacement parts information refer to the Parts Manual.

Motor Brush Inspection

Figure 7-72.Motor Brush, Typical Location

3.Clean brushes and holders. Wipe the commutator with a dry, lint-free cloth. DO NOT USE lubricants of any kind on or around the commutator.

4.Check brush holders for solid connection to the mounting support. Tighten the mounting screws as necessary.

5.Check the cap screws holding the brush cross connectors to the brush holder body.

6.Make sure the motor terminals are secured tightly to the motor frame. Be careful not to strip the threads or crush the insulating parts.

7.Check all the cap screws around the frame for tightness.

8.Keep the outside fram e of the motor clean and free from dirt. Maintain a free air passage around the motor to permit heat radiation.

Motor Brush Replacement

Conduct a partial inspection of the motor after every 1,000 hours of truck operation. If you work in an abnormally severe or caustic environment or if you have a rigorous duty cycle, inspect the motor more frequently.

Set up and rigidly adhere to a strict inspection schedule to obtain the maximum efficiency from the electrical equipment.

Each partial inspection of the motor must include the following:

1.Inspect the brushes for wear and for correct contact with the commutator. Record the level of wear on the brushes. This history gives you an indication of whether a brush must be changed or if it can wait until the next inspection. Refer to page 7-60 for acceptable brush length and general motor information.

NOTE: Overloading a unit is ultimately reflected in the motor and brush wear; therefore, you must take this into account when considering brush replacement.

2.Check brush sp ring tension. See “Motor Brush Spring Tension” on page7-60.

If one brush needs replacement, always replace the entire set of brushes.

Use only genuine Raymond brushes. Using another type of brush could damage the commutator or cause excessive brush wear.

If the end of the brush is not already contoured to fit the commutator, use the following procedure to seat the brush to the commutator.

NOTE: If the motor commutator is not accessible, form the brush contour using a brush seating stone.

1.Move the motor brush springs out of your way.

2.Wrap a piece of 00 sandpaper around the commutator. DO NOT use emery cloth to seat brushes.

3.Move the brushes back down in their holders so that the face of the brushes matches the curve of the commutator.

4.Remove the sandpaper.

5.Blow any dust out of the motor with clean, compressed air at a maximum of 30 psi (207 kPa).

Publication: 1146947, Revised: 12 Jan 2017 7-59

Motor Brush Spring Tension

Brush Spring Tension Inspection

1.If equipped with the optional keypad, press the red OFF ( O ) key. Place the Main ON/OFF Switch in the OFF position. Disconnect the battery connector from the truck.

2.Remove the traction motor cover.

3.Slide the brush up slightly in its holder.

4.Insert a paper strip between the brush face and the commutator. See Figure7-73.

9.Refer to the table below for correct spring tension.

10.Repeat steps 3 through 9 for the remaining brushes.

5.Place a small leather loop around the coil spring for the brush. If the brush spring has a loop at the brush, hook the spring scale directly to the spring.

6.Attach a 5 lb. (2.27 kg) spring scale to the leather loop.

7.While gently pulling the scale outward, slowly pull the paper strip in the direction that the commutator normally rotates.

8.When the paper strip starts to move freely, the spring scale reads the spring brush tension.