detector for two
seconds to reset the
detector to normal.
If the smoke
detector does not
function properly,
call your Smoke
Detector Installer or
Dealer for service.
Smoke Sensitivity
may be measured in
a correlated UL268
or CAN/ULC S529-
M87 smoke box. DSC will conduct this test for a nominal charge. If a
returned unit is found outside of its marked sensitivity range, DSC will
clean and restore the unit’s sensitivity to its marked range.
Smoke sensitivity of installed detectors can be measured without
removal with the Gemini Model 501 Aerosol Smoke Detector Analyzer.
Follow the instructions supplied with the instrument. Start with the
sensitivity corresponding to the lowest marked detector sensitivity; no
alarm should be indicated. Reset with the highest sensitivity setting;
an alarm should then be indicated. These results indicate that the unit
is within its marked sensitivity range. Other settings can be tried to
bracket the detector’s sensitivity to a narrower sensitivity range, such
as may be important during annual tests to quantify any change over
time.
Owner’s Maintenance Instructions
The Meridian Smoke Detector is designed to require a minimum of
maintenance. If the case becomes dusty, wipe the case gently with
a soft dry cloth. If the case is greasy, wipe the case gently with a soft
cloth slightly dampened with soapy water.
Never disassemble the smoke detector; there are no user
serviceable parts inside the unit. Never paint the unit, as paint
may prevent smoke from entering the unit. If you are planning
renovations or repainting, contact your Installer and ask that the
unit be temporarily removed until work is complete.
If the unit is located in an area where it is exposed to high levels of
dust or insects and is found to cause false alarms, it may require
service; contact your Smoke Detector Installer or Dealer.
Guidelines for Locating Smoke Detectors
On smooth ceilings, detectors may be spaced 9.1m (30 feet) apart
as a guide. Other spacings may be required depending on ceiling
height, air movement, the presence of joists, uninsulated ceilings,
etc. Consult National Fire Alarm Code NFPA 72, CAN/ULC-S553-
M86 or other appropriate national standards for installation
recommendations.
Do not locate smoke detectors at the top of peaked or gabled
ceilings; the dead air space in these locations may prevent the unit
from detecting smoke.
Avoid areas with turbulent air flow, such as near doors, fans or
windows. Rapid air movement around the detector may prevent
smoke from entering the unit.
Do not locate detectors in areas of high humidity.
Do not locate detectors in areas where the temperature rises above
38
o
C (100
o
F) or falls below 5
o
C (41
o
F).
Normally, light pulses in the Smoke Chamber
do not reach the light sensor
Smoke in the Smoke Chamber deflects light
into the light sensor, triggering an alarm.
scattered by the smoke and is reflected into the sensor. When
enough light is detected by the sensor, an alarm is activated. On
alarm, the Alarm Indicator Light will come ON and the Detector will
send an alarm signal to the control panel. The Auxiliary Relay, if
equipped, is also activated on alarm.
When the smoke clears from
the chamber, the detector will remain latched in the alarm state
until reset by turning off the power supply from the control panel.
Units with the Temperature Sensor (T) option will activate an
Alarm Indicator Light and auxiliary relay to initiate an alarm at the
control panel also. When the high heat condition returns to
normal, the detector will remain latched in the alarm state until
reset from the control panel. Resetting is achieved by 2 seconds
of power down.
Alarm Indications
Condition
Alarm LED
Aux Relay
No Smoke or Heat
Pulse every
Deactivated
40 s
Smoke or Heat
ON steady
Activated
Sensitivity Test
ON
Activated
Functioning Normally
Steady
Sensitivity Test
Pulse every
Deactivated
Insufficient Sensitivity
40 s
No Smoke or Heat
ON
Activated
but Latched in Alarm
steady
Limitations of Smoke Detectors
While the Meridian Smoke Detector has been designed for reliability,
it is important to know that all smoke detectors have limitations.
• Smoke detectors will not work without power. Devices powered
from a control panel will not function if the control panel’s AC and
battery backup power supplies both fail.
• Smoke detectors can only generate an alarm when smoke gets
inside the Smoke Chamber; anything that prevents smoke from
entering the Smoke Chamber may prevent or delay an alarm. Refer
to the Guidelines for Locating Smoke Detectors on this Instruction
Sheet; it is important that smoke detectors be located on at least
every floor of the premises, preferably in every room. It is also
important to avoid obstructions, such as closed doors, that may
prevent smoke from reaching the unit. A smoke detector will not
detect a fire in the walls, in the chimney or on the roof of a building
until smoke enters the Smoke Chamber.
• Smoke detectors have certain obvious limitations: they may not
provide protection for someone smoking in bed, for children playing
with matches, or for sudden and violent explosions. A smoke
detector is a single part of overall fire safety precautions; the smoke
detector should never be seen as a substitute for a complete fire
safety program.
READ THIS INSTRUCTION SHEET THOROUGHLY BEFORE
INSTALLING AND USING YOUR MERIDIAN SMOKE DETECTOR
Features
• Advanced 90 ° photoelectric detection pattern and specially
designed smoke chamber
∗∗∗∗∗
for superior detection and dust
resistance
• Unique high signal-to-noise ratio and superior RFI immunity to
prevent false alarms
• Excellent smoke access provides reliable detection for all
smoke flow directions and velocities
• Solid-state LED red Indicator Light
• Optional auxiliary relay Form C
• 57°C (135°F) fixed temperature heat sensor option
• Magnet-activated Sensitivity Test Switch
• Attractive styling for any decor
• This symbol on the nameplate means that the product is
listed by Underwriters Laboratories Inc. (UL Standard 268,
Smoke Detectors for Fire Protective Signalling Systems.)
∗∗∗∗∗
Protected under Canadian patent No. 1452296. Other patents pending.
Models
MN220
2-Wire Detector
MN220T
2-Wire Detector and Fixed Temp 57
o
C (135
o
F) Sensor
MN220R
2-Wire Detector and Auxiliary Form “C” Relay
MN220RT
2-Wire Detector and Auxiliary Form “C” Relay and Fixed
Temp 57
o
C (135
o
F) Sensor
Introduction
The DSC Meridian MN 220 Series Smoke Detectors are two-wire
smoke detectors intended for open area protection. They are suited
for commercial and institutional fire alarm systems.
The DSC Meridian Photoelectric Smoke Detector incorporates many
advanced design features to provide years of reliable operation. It
is important to follow the Installation and Operation instructions on
this sheet to ensure that the unit will function properly — even the
best designed smoke detector will be rendered useless if it is not
connected or located properly.
It is very important that you understand how to test and maintain your
system. Refer to the Instruction or User Manual for your alarm
system, and familiarise yourself with how the Fire Alarm functions of
your system operate. Be sure to test your system regularly following
the test procedures described in your manual. If you should ever
have problems operating or testing your system, and especially if
there are problems with the Fire Alarm functions, contact your Smoke
Detector Installer or Dealer immediately for service.
While smoke detectors and alarm systems are designed to warn you
of potentially dangerous situations, no system can prevent
emergencies. An alarm system is not a substitute for life and
property insurance; you should always maintain appropriate
insurance coverage.
How the Smoke Detector Works
As shown in the illustration, a light source is directed across the
smoke chamber and is not normally reflected into the sensing
element. When smoke enters the chamber, the light beam is
Smoke detectors should always be installed in accordance with NFPA 72, the
National Fire Alarm Code. Smoke detectors should always be located in
accordance with Paragraph 2.1.1.1 of NFPA 72, Chapter 2.:
“2-2.1.1.1 Smoke detectors shall be installed outside of each separate
sleeping area in the immediate vicinity of the bedrooms and on each
additional story of the family living unit, including basements and excluding
crawl spaces and unfinished attics. In new construction, a smoke detector
also shall be installed in each sleeping room.”
Photoelectric
Sm oke Detector
INSTRUCTIONS FOR
INSTALLATION AND USE
M N - 2 2 0 S E R I E S 2 - W I R E S M O K E D E T E C T O R S
Bedroom
Bedroom
Basement
Living
Room
Dining
Room
NEVER
HERE
Acceptable
here
Top of detector
acceptable here
12"
(0.3m)
Max.
4"
(0.1m)
Max.
4"
(0.1m)
Ceiling
Wall
NOTE: Measurements shown are to
the closest edge of the detector.
Figure 2
Bedroom
Bedroom
Bedroom
Living
Room
Kitchen
Dining
Room
Family Room
Figure 1
Bedroom
Bedroom
Bedroom
Living Room
Kitchen
Figure 4
Figure 3
Fire Safety In The Home
Most fires occur in the home, and to minimize this danger, it is
recommended that a household fire safety audit be conducted and
a family escape plan be developed.
Household Fire Safety Audit
1 Are all electrical appliances and outlets in a safe condition? Check
for frayed cords, overloaded lighting circuits, etc. If you are
uncertain about the condition of your electrical appliances or
household service, have a professional evaluation.
2 Are all flammable liquids stored safely in closed containers in a
cool, well ventilated area? Cleaning with flammable liquids should
be avoided.
3 Are hazardous materials such as matches out of the reach of
children?
4 Are furnaces and wood burning appliances properly installed,
clean and in good working order? If in doubt, have a professional
evaluation.
Family Escape Planning
There is often very little time between the detection of a fire and the
time it becomes deadly. Because of this, it is very important that a
family escape plan be developed and rehearsed.
Testing Your Smoke Detector
Test the detector for minimum sensitivity by activating the test feature.
To test the unit, hold the test magnet against the case as shown. The
Alarm Indicator Light will come ON, the Auxiliary Relay (if equipped) will
be activated, and the alarm control panel should indicate a fire alarm.
When the magnet is removed, the Alarm Light and Auxiliary Relay will
remain ON. Turn off the voltage supply from the control panel to the
