M
ODEL
RDP-12
R
EMOTE
M
OUNT
D
UAL
B
LOWER
B
UILDING
P
RESSURIZATION
U
NIT
600 Gulf Freeway
Texas City, TX 77591
PHN: (409) 935-5743
FAX: (409) 938-4189
Copyright © 1996 - Bebco Industries, Incorporated - All Rights Reserved
Environmental Control Units Division
Bebco Industries
ECU Division Technical Bulletin RDP-12-R1.0
05/97
Opening: 21 Sq Ft Maximum
Area: 80 Sq Ft Maximum
Technical Description
Model RDP-12 is a remote-mount
pressurization unit for control rooms or buildings
containing no internal source of flammable vapors
or gases. The unit utilizes a primary and secondary
fan to pressurize rooms or buildings with opening(s)
not exceeding a total of 21 square feet and a floor
area not exceeding 80 square feet. The primary
fan is controlled by a variable speed drive to maintain
a safe (0.25") pressure when the doorway is sealed.
The secondary fan engages upon loss of safe
pressure, to generate a minimum air velocity of
sixty (60) feet per minute through the doorway, and
functions as a redundant fan if the primary fan fails.
This unit, combined with an intake system that
draws fresh air from a nonhazardous area, reduces
the hazardous (classified) area rating within the
room or building from Class I, Division 1 or 2 to
nonhazardous, in accordance with NFPA 496,
Chapter 5.
Basic Operation
Unit must be powered by a local disconnect
switch connected ahead of building power or
connected to a separate power source. The unit is
started by closing the building door and placing the
secondary fan switch in the "automatic" position
and the primary fan switch in the "on" position. The
primary fan then engages to regulate air flow and
maintain a safe pressure. When the door is opened,
pressure will fall below the alarm setpoint. The
primary fan will then increase velocity, and the unit
will activate an alarm signal delay timer and a
secondary fan delay timer. These timers are field-
adjustable to permit immediate or delayed response
to changes in pressure. Both timers are activated
and reset as pressure falls below and rises above
the alarm setpoint. If the secondary fan or alarm
engages, they disengage when the door is sealed
and pressure rises above the alarm setpoint.
DIVISION 1 AREA APPLICATION NOTE:
INSTALLER MUST PROVIDE DISCONNECT EQUIPMENT TO
AUTOMATICALLY REMOVE POWER FROM ALL NONRATED
DEVICES, UPON FAILURE OF THE PRESSURIZATION UNIT.
Standard Controls
Primary Fan "On" Indicator
- indicates that primary fan is engaged
- flashes when the ESD or ECO is engaged
Primary Fan Control Switch
- engages and disengages primary fan
Secondary Fan Control Switch
- off, manual and automatic positions
Alarm "Engaged" Indicator
- indicates alarm signal is active
- flashes when alarm signal is bypassed
Alarm Signal Bypass Switch
- allows bypass of alarm relay
RDP Horizontal Side
Angle View
Control Enclosure
