December 2008
Section 4 Installation
Page 4 – 8
Amerex Restaurant Fire Suppression System (EX 4658)
INSTALLING THE DETECTION NETWORK – MRM or MRM II
Refer to the system design section for Detector Network limitations. There is only one type of detector
bracket and linkage used with this system. There are, however, two names for detectors in the network –
series and terminal. The terminal detector is the detector located at the end of the cable run, furthest away
from the MRM or MRM II. A series detector is any detector located in between the MRM or MRM II and the
terminal detector in the network.
Starting at one of the corresponding knock-out found on one of the two available sides (top or bottom) of the
MRM or MRM II. Install ½” EMT conduit running from the MRM or MRM II to each detector location, using a
corner pulley at every change in direction. Each detector must be securely fastened to a rigid surface,
located over each protected appliance and in the hood / duct opening. Refer to the Design section for
limitations and cautions regarding detector placement.
INSTALLING THE DETECTION NETWORK – MRM II
Setting Detection Cable Tension, New MRM II (P/N 18000 and 18001):
Refer to the following images in this section for properly setting the detection cable tension:
1) To set the tension on the cable, first make sure that the tension bar in the MRM II is in the “down” position
and that the spring is relaxed. Lower the top hook of the blue spring into the bottom of the tension bar slot.
Warning: Do NOT attempt to set the tension bar in the “up” position (spring stretched) without
having a fusible link line installed and secured or the MRM will fire. Take additional caution; DO NOT
install the Nitrogen Actuation Cylinder at this time.
2) Feed the cable end into the small hole in the side of the ratchet pulley. The end of the cable must be
cleanly cut. Push the cable into the hole until the end is visible at the head of the central hex-bolt. Securely
tighten the Allen-head set screw onto the cable. Aside from the use of the cocking tool, no further tools
should be used to set the mechanism. (The cable may be routed from either the bottom or the top of the MRM
II; the ratchet pulley will always turn counter-clockwise to remove cable slack. – See illustration on Page 4-9A)
3) Spool up the excess cable slack by turning the ratchet pulley counter-clockwise by hand. Continue to hold
the ratchet pulley while proceeding to the next step.
4) While maintaining the position of the ratchet pulley with your left hand, press down on the engagement
pawl and the linkage bar with your index and middle fingers of your right hand in order to begin the final
tensioning process. You will feel and hear the pawl click several times as tension is taken up.
5) Inspect your progress by pulling the upper hook of the blue spring into the top notch of the tension bar;
then raise the tension bar. Refer to the illustrations on the following page for proper setting
.
Repeat steps 1-
5 until the bottom of the linkage bar is essentially horizontal, and is aligned within the gray “pie” zone of the
indicator label (see Figure B).
Lower tension bar until system is ready to test
.
To test the Detection Network, refer to Chapter 5, “Testing and Commissioning”.
Position link holder and link
in center (or slightly off center
away from MRM) in bracket
To install the cable, start at the terminal detector, affix
the Cable with a terminal clamp (P/N 12859 provided
with the MRM & MRM II) leaving a minimum of 6
inches between the end of the cable and the terminal
clamp. From the terminal detector, continue to feed the
cable through each corner pulley, detector and length
of EMT conduit back to the MRM.
Terminal Clamp
(P/N 12859)
