SYSTEM COMPONENTS
2012-MAY-18 REV. 02 PAGE 3
CHECKFIRE MP-N Electric
Detection and Actuation System Manual
CONTROL MODULE
The Control Module, Part No. 427300, is the basis of the
CHECKFIRE MP-N detection system. The module cover and back
box is made of durable Noryl SE1gfN3 material with a flam mability
rating of UL94 V-1. The back box contains the field interface termi-
nal block, battery, and field wiring entrance ports. The cover
assembly contains the control PC board assembly, sounder, oper-
ator interface panel, and environmental seal. The enclosure meets
International Standard IEC 529 requirements for dust and water
spray in all directions. Mounting pads allow mounting to any suit-
able flat surfaces. Steel mounting brackets are also available.
All circuitry, relays, switches, and LEDʼs are contained on a single
PC board. A board mounted receptacle mates with the plug-in
terminal block mounted in the back box. A high pitch sounder is
threaded into the cover and plugged into the PC board. The PC
board is encapsulated to provide added protection against mois-
ture and dust. An RS232 interface cable connector is provided for
field programming from a PC and for data retrieval from a trouble
and alarm history buffer. The PC board assembly contains a DIP
switch for optional manual programming functions without the use
of a PC. See Figure 2.
When installed in an area that is classified as hazardous in
accordance with the NEC Article 500, only equipment that has
been approved for use in those areas can be used. This require-
ment applies to programming equipment such as PCs that may
be used to program the CHECKFIRE MP-N.
FIGURE 2
002755
MANUAL AND AUTOMATIC ACTUATORS
The MSHA CHECKFIRE MP-N system is equipped with both
manual and automatic agent release devices.
Manual Actuator
A 1/4 in. NPT street elbow is supplied with the actuator for conve-
nient connection of the 1/4 in. actuation line to the fire suppression
system.
The manual actuator is designed with a RED palm button which is
attached to a cartridge seal piercing pin and a ring pin to guard
against accidentally piercing the cartridge seal. To initiate agent
release, the operator must pull out the ring pin and strike the RED
palm button. The manual actuator must be located near the oper-
atorʼs control station. See Figure 3.
PART NO. 416792
FIGURE 3
003912
Automatic Actuator
The MSHA CHECKFIRE MP-N controller is provided with an agent
release output which automatically and electrically actuates a gas
motor as a result of a detected fire condition.
Automatic actuation is accomplished using the gas motor to pierce
the seal of a nitrogen cartridge. The gas motor is made up of a
miniature gas cylinder with piston and rod, a chemical charge and
an electrical heating element.
When the heating element is energized by a small current from the
control module, the chemical charge is ignited, generating a gas
which drives the piston and rod outward. The gas produced by
ignition also locks the piston and rod in the outward position.
The piston rod pushes the cartridge seal puncture pin through the
cartridge seal to release the high pressure cartridge gas. The
release of the cartridges gas in turn pressurizes the agent tank
which causes agent release.
The gas motor must be replaced with gas motor replacement ship-
ping assembly, Part No. 416756, after firing.
The gas motor actuator, Part No. 416735, can be installed
remotely from the operatorʼs control station. See Figure 4.
PART NO. 416735
FIGURE 4
003913
!
CAUTION
RING PIN
1/4 IN. NPT
STRIKE
BUTTON
GAS MOTOR
ACTUATOR
1/4 IN. NPT
