Page 8 - F10-BPS-YZ101B-Installation-Manual

Pressurization Unit & Switch Set Up

Pressurization Unit Set Up Pressure Switch Set Up

1. Ensure Protected Enclosure Power is OFF, Enclosure 1. The following directions are for purge models with the
Pressure Control Regulator is closed and Protective suffix -W or -B which are supplied with a flame proof
Gas Supply is ON. differential pressure switch (DPS).
2. Adjust Redundant Regulator, if utilized, to 5 psi maximum IMPORTANT NOTE
or skip to step 3 if enclosure is equipped with a Model
PV-3 Purge Vent. The differential pressure switch is intended solely for loss
3. Test Purge Vent, if utilized. Using the eraser end of a of safe pressure alarm and should not be used to control
pencil or similar object, insert from inside the enclosure power to the protected enclosure.
to confirm vent relief ball is operating properly. Note:
Side mounted, Model PV-3-S, remove plug from bottom 2. Connect alarm system wiring to the DPS via rigid
of tee fitting to test vent. conduit and seal or other approved wiring method for
4. Close and Seal Protected Enclosure. the classified location.

5. Slowly turn Enclosure Pressure Control Regulator 3. The DPS provides a Form C Dry NO, NC and C contact.
CW until a “Safe” 0.5” w.c. reading is shown on the Note: -B switches require 120 VAC or 24 VDC power to
Enclosure Pressure Gauge. Note: If unable to achieve a operate.
“ Safe” enclosure pressure, carefully check all enclosure 4. The alarm system should be connected in a fail safe
connections and doors for leakage. Seal as needed. configuration.
6. Class I, confirm and document Protective Gas flow shown
on temporarily installed flow meter. Use formulas below
to determine purge time required, 5 minutes minimum.
(Total Enclosure Volume x 4)/Flow Rate Typical Pressure Switch Wiring Diagram
(Total Enclosure Volume x 5)/Flow Rate
7. Mark purge time on Unit start up instruction name tag C NO NC
using a permanent marker.
8. Set up is complete. Remove any test equipment and
proceed to Optional Enclosure Pressure Switch Set up
if required.

Customer Supplied Alarm

Cross Ventilation Diagram

(optional)
Protective Purge Vent
Gas Supply
Header Enclosure Reference Tubing

Protected
Protected Enclosure(s)
Enclosure(s)
Purge Protected
Unit Enclosure(s)
Unit Supply Tubing

Page 8 of 14 BPS YZ101B IOM-R1.0 © 2018 - Best Purging Systems Corporation