Usage:
CONFIDENTIAL TIBU4491-01
TECHNICAL INFORMATION BULLETIN |
April 13, 2005 |
Gen Sets |
This Technical Information Bulletin replaces the March 16, 2005 TIB "Potential Problems with Larne and Griffin Gensets". Disregard the March 16, 2005 TIB. Refer to the following information.
3406C (C2G1-1223, C5G1-0176) 3456 (C1G1-0626, C3G1-0191, C4G1-0163) C-18 (G4C1-0392) |
Component Code(s) 1404 |
SUBJECT:
Potential Problems with Larne and Griffin GensetsPROBLEM:
On the above listed Gen Set, power looms can become damaged at various places between the generator and the breaker, either during assembly or during use in the field. Also, the insulation may become pulled back from the termination, resulting in an exposed copper braid.
1. Insulation exposing copper braid. Insulation may become exposed during assembly or shortly afterwards, as shown in Figure 1. This is addressed in the solution below.
Figure 1
2. Protection against chaffing/scratches. The loom insulation may become damaged due to chaffing and/or scratches, either at assembly or during re-configuration of the genset in the field. This is shown in Figure 2. This is addressed in the solution section below.
Figure 2
3. Loom termination fixing onto generator busbar. The insulation on the loom may come into contact between the generator busbar and the face of the loom terminal, as shown in Figure 3. This is addressed in the solution below.
Figure 3
4. Generator looms making contact with adjacent busbar. If there is excess length of the looms within the generator, it is possible that one loom may come into contact with an adjacent generator busbar. Over time, wear may occur, resulting in a short circuit between phases. See Figure 4. This is addressed in the solution section below.
Figure 4
SOLUTION
:1. Insulation exposing copper braid. To prevent the sleeving from moving, exposing the copper braid, follow the steps below:
- Cut back the sleeve to expose approximately 100mm (3.9 inches) of copper braid at each end.
- Fit 2 200mm (7.9 inches) lengths of heat shrinkable tubing (one at each end) to cover both the copper braid and the sleeving. The part number for the heat shrinkable tubing is 7X2639 that has an internal diameter of 50.8 mm (2 inches) before shrinkage and a minimum of 25.4 mm (1 inch) after shrinkage.
- Apply hot air to the heat-shrink tubing to shrink it securely on to both the braid and the sleeve.
The result should be similar to Figure 5.
Figure 5
Generator looms making contact with adjacent busbar.
- To prevent the looms coming into contact with adjacent generator busbars, first add heat-shrink tubing as shown in Figure 5. This should make the loom sufficiently stiff that it should not easily fall and come into contact with the adjacent busbar.
- Using cable ties, ensure that the looms are secured at a good distance away from the adjacent busbars.
Loom termination fixing onto generator busbar.
At present, there is not other solution to ensuring that there is sufficient contact between the busbar and the loom termination, for field gensets, than to follow the step below.
Ensure that the screws are tightened to the following torque:
M6 8.9 lb (+/-2.2 lb) [12Nm(+/-3Nm)]
M10 34.7 lb (+/-6.6 lb) [47Nm (+/-9Nm)]
Protection against chaffing/scratches
- Add 4 (part number 7H-8213) rubber mats to loom as they enter the control panel as shown in Figure 6 to insulate the looms from the chassis.
- Secure the mats to the looms with 8 (part number 113-8604) band ties.
- Add 4 (part number 7H-8213) rubber mats to looms as they enter the turret as shown in Figure 7 to protect the looms from chaffing.
- Secure the mats to the looms with 8 (part number 7K-1181) cable strap.
- Add 1 (part number 7H-8213) rubber mat to the center loom to insulate it from the other two phase looms, where the other two phase looms are cable-tied to it, as shown in Figure 8.
- DO NOT secure the mat with a (part number 7K-1181) cable strap.
- Add 1 or 2 (part number 7H-8213) rubber mats as required around the three phase looms, as shown in Figure 9.
- Secure all mats with 2 (part 7K-1181) cable straps.
- Add 1 (part number 7H-8213) rubber mat around the neutral loom where it meets the opening in the top of the alternator housing as shown in Figure 10.
- Secure the mat with 2 (part number 7K-1181) cable straps.
Figure 6
Figure 7
Figure 8
Figure 9
Figure 10
Note: The turret mats should then similar to that shown in Figure 11.
Figure 11
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