Roof Preparation; Wiring Requirements; Placing Unit On Roof - Dometic 459146.70X Installation & Operating Instructions Manual

INSTALLATION INSTRUCTIONS
B.

Roof Preparation

1.   FIRE OR ELECTRICAL SHOCK
HAZARD. Verify there are no obstacles inside
RV's roof and/or walls (wires, pipes, etc.). Shut
OFF gas supply, disconnect 120 Vac power from
RV and disconnect positive (+) 12 Vdc terminal
from supply battery BEFORE drilling or cutting
into RV. Failure to obey these warnings could
result in death or serious injury.
 O pening Requirements - Before prepar-
ing the ceiling opening, read all of the fol-
lowing instructions before beginning the
installation.
If an existing roof vent opening will NOT
be used a roof opening MUST be cut
through the roof and ceiling of the RV.
This opening MUST be located between
the roof reinforcing members.
2. Roof vent removal
a. Unscrew and remove the roof vent.
b. Remove all caulking compound around
opening.
c. Seal all screw holes and seams where the
roof gasket will be located. Use a good grade
of all weather sealant.
d. If the opening exceeds 14-3/8" x 14-3/8", it
will be necessary to resize the opening. See
"B. Roof Requirements" on page (4).
e. If the opening is less than 14-1/8" x 14-1/8",
it must be enlarged. See "B. Roof Require-
ments" on page (4).
3. New opening
a. Carefully mark and cut the required roof
opening. See "B. Roof Requirements" on
page (4).
b.  Maintain structural integrity.
Otherwise damage to product and/or RV
could occur.
 NEVER create a low spot on
RV roof. Otherwise, water will pool and could
cause a leak.
Using the roof opening as a guide, cut the
matching hole in the ceiling.
The opening created must be framed to pro-
vide adequate support and prevent air from
being drawn from the roof cavity. Framing
stock 3/4" or more in thickness must be used.
Remember to provide an entrance hole for
power supplies at the front of the opening.
See (FIG. 4).
FIG. 4
Do Not Cut Roof
Structure Or
Rafters
3/4" Min.
Leave Access For
Power Supply Wiring
C.

Wiring Requirements

1. Route a copper, with ground, 120 Vac supply
wire from the time delay fuse or circuit breaker
box to the roof opening. Use a listed/certified
non metallic - sheathed single strand cable. The
proper size wire can be determined from chart
on page 4.
 I f vent fan was removed, the existing wire
may be used provided it is of proper type,
size, location, and correctly fused.
a. This supply wire must be located in the front
portion of the roof opening.
b. The power MUST be on an appropriately
sized separate time delay fuse or circuit
breaker. The proper size protection can be
determined from chart on page 4.
c. Make sure that at least 15" of supply wire
extends into the roof opening. This insures
an easy connection at the junction box.
d. Protect the wire where it passes into the
opening with approved method.
D.

Placing Unit On Roof

1. Remove the unit from the carton and discard
carton.
2.  LIFTING HAZARD. Use proper
lifting technique and control when lifting product.
Failure to obey this caution could result in injury.
Place unit on the roof.
6
Good-Rafters Good Location
Supported By Between Roof
Rafters
Cross Beams
Frame Opening So It
Won't Collapse When
Bolting Down Unit
15" Min. At
Front Of
Opening