GP, Explosion-Proof and FMS Lab Refrigerators and Freezers
Installation | 11
How to Seal Killark® Box
Conduit
To Seal Killark® Box Conduit with Fiber and Sealing
Compound to Help Protect Against Explosions (Explosion-
Proof Units Only):
The purpose of the procedure that follows is to build fiber
rope dams on the left and right hubs of the horizontal conduit.
The fiber rope damns will surround conduit wiring that is
housed inside the horizontal conduit. When both the left and
right fiber rope dams have been pressed into place, sealing
compound is poured between the two and forms into an
airtight plug.
All of this is done in order to prevent the very real threat of gas
entering the Killark box and a resulting serious explosion. After
the unit wires have been pulled through the horizontal conduit
the following procedure is required:
•
Turn power off at the circuit breaker before proceeding.
•
Place a small amount of sealing compound granules,
enclosed, into a clean mixing vessel. Add small amounts
of water while stirring until a thick paste is formed, then
carefully continue adding smaller amounts of water until a
thick gravy consistency is achieved—NOT WATERY.
Discard any material that becomes too stiff to use. Never
attempt to restore workability by stirring in more water.
•
Locate silver Killark box, back/top-center of unit.
•
Unscrew conduit domed-cover.
Unscrew and Remove Cover
Conduit
Horizontal
Left Hub
Right Hub
Conduit
Opening
Conduit Domed-Cover
Note:
KILLARK® is a registered trademark of Hubbell
Incorporated, Shelton, CT, USA.
Figure 1. Sealing the Killark Box
Note:
Wires must be kept separated as shown in the
Left Hub
Right Hub
Wiring
Figure 2. Horizontal Conduit, Cutaway
•
Insert fiber rope material down into horizontal conduit
opening. Pressing down firmly, work the material into the
left hub and—most importantly—being sure the material
COMPLETELY SURROUNDS THE WIRING, from the top
to the bottom, completely blocking this end of the
horizontal conduit.
Figure 3. Fiber rope material in left hub
•
Insert fiber rope material down into horizontal conduit
opening. Pressing down firmly, work the material into the
right hub and—most importantly—being sure the
material COMPLETELY SURROUNDS THE WIRING, from
the top to the bottom, completely blocking this end of the
horizontal conduit.
Figure 4. Fiber rope material in right hub