6.24.2 Cracks

Cracks in the control box are repaired using a fiberglass patch over the damaged area. Materials required are included in the Fiberglass Patch Kit supplied with Crack Repair Kit, Carrier Transicold part number 76-00724-00SV (see Table 6-3).

a.The surface must be clean and dry. Roughen the sur- face with sandpaper to ensure a good bond.

b.Cut the fiberglass cloth to allow a 25mm (1-inch) overlap around the area to be repaired.

c.Stretch and position the cloth over the area to be re- paired and secure it with masking tape.

d.Make up sufficient epoxy glue to cover the cloth by mixing equal parts of resin and hardener. Saturate the cloth with the epoxy glue, spreading evenly.

e.Remove the tape and overlap the edge of the cloth approximately 6 to 12 mm (1/4” to 1/2”) with glue.

f.Epoxy will dry in 45-60 minutes. When completely cured (12 hours), use sandpaper to smooth edges of the patch.

6.24.3 Chips And Holes

Chips and holes in the control box are repaired using a piece of aluminum or stainless steel to cover the damaged area. The material can be cut to suit and riveted in place. An adhesive sealant must be used to make the repair watertight. The adhesive sealant (Sikaflex 221) is included in Crack Repair Kit Carrier Transicold part number 76-00724-00SV (see Table 6-3). Do not use an acetone based silicone sealant (Which can be identified by a vinegar-like odor).

a. To make up the patch, cut a piece of aluminum or stainless steel so that it will overlap the damaged area by at least 40 mm (1 1/2”) on all sides.

b. Choose rivet locations and drill the rivet holes in the corresponding locations on the control box and patch piece.

c.Apply the adhesive sealant around the damaged area to form a seal between the control box and the patch piece.

d.Rivet the patch piece in place.

e.File smooth any rough edges (including rivets) that may come into contact with wires.

6.24.4 Inserts

The threaded brass inserts that are molded into the control box will need to be replaced if the threads become stripped, or if the insert becomes loose. The inserts and epoxy are contained in repair kit, Carrier Transicold part number 76-50084-00 (see Table 6-4). There are 6 different inserts used in the control box. Refer to Figure 6-24 for the locations of the various inserts.

NOTE

An epoxy application gun is also needed, Carri- er Transicold part number 07 - 00391 - 00.

The damaged insert must be removed from the control box. Table 6-5 identifies the drill size and drill depth to be used for each insert. A stop ring should be used on the drill bit to limit the depth.

a. Center the drill bit on the insert and drill to the pre- scribed depth.

b. Remove the chips from the drilled hole.

c. Mix the two component epoxy and fill the hole 1/2 way to the top with epoxy.

d. Press the insert in until it is flush with the surface.

e. Wipe away any excess epoxy. The part is ready for service after the bond material has hardened and is tack free (approximately 20 minutes)

6.24.5 Door Hinge Inserts

If the door hinges have been pulled from the control box drill and reinstall the hinge as shown in Figure 6-23 and described in the following steps.

Figure 6-23 Door Hinge Repair

Materials needed:

1.Cut two square pieces of 3 mm thick (1/8 inch) alu- minum or stainless steel approximately 40 mm (1 5/8”) square. These squares will serve as backing plates.

2.Two nuts, bolts (10 - 24 x 1”) and washers for each insert that needs repair.

a.Drill a 1/4” hole in the center of each square backing plate.

b.Pass the bolts through the bolts holes in the door hinge, then through the control box at the location where the hinge insert pulled out.

c.From inside the control box, slide the backing plates over the bolts and secure in place with the washers and nuts.

6-19

T-309

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Carrier 69NT20-531-300 manual Door Hinge Repair

69NT20-531-300 specifications

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