150-458-100-05
Installation
HRE-458 List 1, List 1B, and List 2
February 23, 2000
17
O
PENING
THE
HRE-458 E
NCLOSURE
To open the HRE-458, perform the following steps:
1
To open a gel-filled List 1, List 1B enclosure which is not being pressurized, go to Step 7. To open a gel-filled
List 1, List 1B enclosure which is being pressurized, go to Step 3.
2
To open an air-filled List 2 enclosure, go to Step 5. Steps 3 and 4 relate to the pressurized List 1, List 1B
enclosure.
3
Turn off the external pressure supply, if possible. Locate the pressure cutoff valve as shown in
. If the external pressure supply is off, verify that the pressure cutoff valve is in the open position
(rotated counterclockwise) which is the normal position when operating a gel-filled enclosure in a pressurized
application. If you are able to turn the external pressure supply off, go to Step 6. If you are unable to turn the
external pressure supply off, close the pressure cutoff valve by rotating clockwise one (1) full turn, blocking
the pressure from the external source. Go to step 4.
4
Unlock the enclosure. Gently push the dome cover back and forth while loosening the cover clamp until the
seal is broken and the pressure is released. The seal should break well before the cover clamp is loosened
enough to allow the cover to separate from the enclosure. Go to step 9.
5
Locate the pressure cutoff valve as shown in
. Close the pressure cutoff valve by rotating
clockwise one (1) full turn, blocking the pressure from the main cable.
6
Depress the center pin of the air stem to release the remaining pressure within the enclosure.
7
Unlock the enclosure.
8
Loosen cover clamp and twist the stainless steel dome slightly to break seal.
9
Remove the cover clamp.
10
Remove the stainless steel dome from the enclosure.
C
LOSING
THE
HRE-458 E
NCLOSURE
1
Inspect the enclosure cover for dirt, moisture, or mechanical damage especially around the flange which
mates with the baseplate and O-ring. Remove any accumulation of dirt or moisture from the cover. Replace
any damaged components.
2
Inspect the baseplate for dirt, moisture, or mechanical damage especially around the baseplate flange.
Remove any accumulation of dirt or moisture from baseplate.
3
Remove the desiccant pack from the plastic storage bag and place it in the enclosure.
4
Fasten the slot retainer bracket in place.
5
Slide the stainless steel dome over the card cage and position it on the O-ring and baseplate.
6
Lubricate the threads of the cover clamp T-bolt with antiseize compound.
When handling any enclosures, always assume they are pressurized. Failure to relieve the
pressure before removing the cover could result in serious personal injury.
Exercise care when removing and handling the stainless steel dome. A damaged stainless steel
dome may not seal properly when replaced.
