Model 1011
Installation and Operation Manual
15
Par
t No
. 51
2083 Dra
wing No
. 1
29-0205a 03/09
Operating Sequence
WARNING! Do not exceed a “safe” pressure with the
enclosure pressure control regulator. Operators must
follow step-by-step sequence of the start-up instructions
nameplate on the protection system.
Class I Purging Operation
Start-Up Conditions
Protection method:
Type “Z” purge/pressurization system
Powering method:
Local disconnect switch
System status:
Protected equipment de-energized
alarm system and air supply on
Operating Procedures
1. Check operation of enclosure pressure relief device (if
utilized) and seal the protected enclosure.
2. Pressurize the protected enclosure to set and maintain a
minimum positive pressure of 0.10 inches (2.5 mm) of water.
3. Exchange the recommended volumes of purging gas.
Exception: Power may be energized immediately if
the protected enclosure atmosphere is known to be
nonflammable.
4. Energize the protected equipment power manually with
a disconnect switch or breaker rated for the hazardous
location.
5. Loss of pressurization requires immediate attention or the
manual de-energizing of protected equipment power.
6. Excessively hot equipment must be isolated in a separate
protected enclosure, unless the enclosure is marked with a
warning which indicates a required cool-down time period
before access.
Class II Pressurization Operation
Start-Up Conditions
Protection method:
Type “Z” pressurization system
Powering method:
Local disconnect switch
System status:
Protected equipment de-energized
alarm system and air supply on
Operating Procedures
1. Remove hazardous substance from the protected enclosure.
A vacuum device is the preferred tool for dust removal.
2. Check operation of enclosure pressure relief device (if
utilized) and seal the protected enclosure.
3. Pressurize the protected enclosure to set and maintain a
positive pressure of 0.50 inches (12.7 mm) of water.
4. Energize the protected equipment power manually with
a disconnect switch or breaker rated for the hazardous
location.
5. Loss of pressurization requires immediate attention or the
manual de-energizing of protected equipment power.
6. Excessively hot equipment must be isolated in a separate
protected enclosure, unless the enclosure is marked with
a warning that indicates a required cool-down time period
before access.
Enclosure
pressure
control
regulator
Model
identification
nameplate
Enclosure
pressure
gauge
Start-up
instruction
nameplate
