Introduction
General Description
The Brasch Environmental Technologies GDCP-Touch Gas Detector Control Panel is designed
to function as a complete ventilation control system. These systems can be as simple as a
panel and one transmitter controlling one ventilation fan, or as complex as a panel with 128
sensors controlling 32 zones worth of ventilation equipment.
The control panel itself consists of a touchscreen display, a relay control board, and digital
control circuitry. The panel monitors the signal from the transmitters, compares the signal to
preset values, and controls relay contacts based upon the comparison. These relay contacts
then provide signals that control ventilation components such as exhaust fans, louvers, and
dampers. The touchscreen provides a visual indication of the system’s operational condition
along with an intuitive interface for configuring the entire system. A linear proportional output is
also included for communication with a building management system (BMS), direct digital
controls system (DDCS), or variable-frequency drive (VFD).
The sensors used in the remote transmitters operate on the electrochemical principle and are
able to detect carbon monoxide or nitrogen dioxide. A current is produced when the target gas
reacts chemically with an electrode inside the sensor. This small current is converted to an
analog voltage, amplified, and converted to a digital signal. This signal is proportional to the
gas concentration present at the sensor and is shown on the display. After comparing the
digital signal to preset values, the panel updates the display and relays.
The GDCP-Touch housing has a NEMA 4X rating and is supplied with knockouts so that the
control panel can mount directly to a standard four inch conduit box. A hinged cover secured
by two screws makes it easy to gain access to the touchscreen for system configuration. A
secondary, interior hinge affords access to the relay board, allowing power, communication,
and relay connections to be made.
The GDCP-Touch can also accept additional relay boards in the form of GDCP-
ExpansionPacks. These provide four more relays for added control along with another analog
output and a signal repeater to extend the range and sensor capacity. GDCP-PowerPacks
may be added to convert AC line voltage to the low voltage required to power the control
panel, transmitters, and relay boards.
IOM03
Rev 1.1 – May 18, 2021
5
