Duct Detector FAQs

Duct Detector FAQs | Duct Smoke Detection Systems | APC

Have questions about duct smoke detection in heating, ventilation, and air conditioning in an HVAC System? Visit APC’s Duct Detector FAQs to learn more.

 

SL-2000 is powered but no lights are showing

Check power is good, probe across terminals 9 and 10, check for roughly 24V.
Check detector head is seated, rotate counterclockwise and reattach it by turning clockwise until it’s seated.
Check transparent lid, ensure it is fitted and not ajar and all screws are tightened, SW1 can be inspected for damage if the lid has been installed incorrectly previously.

Interconnected Wiring

SL2000 terminals 12 and 20 must be connected between all detectors desired to be interconnected, a common power source must be used such that all detectors interconnected must be powered from a common 24VAC transformer, or mains power circuit. LEDs wont light up but the relay will click.
For a common remote for common test/reset, 1 and 20 must be connected between all desired detectors. LEDs will light up

Wiring the SL-2000 as a fire system contractor

In a typical class B fire alarm configuration wire one wire from your fire alarm panel to terminal 13 and the other to 14. Make a wire jumper from terminal 13 to terminal 5 and place your end of line resistor to terminals 14 and 15.
For applications of multiple duct smoke detectors on a single fire alarm circuit, all alarm contacts must be wired to the panel in parallel with all trouble contacts wired in series with the end of line resistor on the very last detector. Refer to Page 4 of the installation guide for wiring diagram.

Wire the SL-2000 to an HVAC system

Alarm contact terminals 16 and 6 (normally closed and common) can be used to break the red 24V power wire to the thermostat.
16 and 6 effectively works as a switch, in a normal condition 16 is connected to 6 and when in alarm 16 is disconnected from 6.
Some residential furnaces have a fan rundown mode where the fan will run even after a signal from the thermostat, these furnaces sometimes have a DIL switch to program this feature or alternatively power can be broken to the furnace alternate to the thermostat by breaking the neutral power to the furnace through terminals 16 and 6.

SL-2000 for residential furnace use

For 24v, wire break the wire from the furnace and the thermostat. Connect the wire from the thermostat to 16 and the wire from the furnace to 16. Use the 24v transformer from the furnace. The 24v to terminal 10 and the common connects to terminal 9. For 115

Operational testing the SL-2000

MAGNET TESTING: Place the magnet on top of the housing between the raised sections above the detector head (as indicated by the arrows on the unit cover). Allow at least five seconds for alarm initiation. Remove magnet and reset detector.
SMOKE TESTING: Using smoke test canister with testing nozzle (part number TG-2000 or ), insert the test gas nozzle into the test port on the unit cover. Press can against cover to release gas into the chamber. After 15 to 20 seconds the detector head will go into alarm, illuminating the detector head LED and causing the duct unit functions to operate, alarm relays will change state, and the alarm related remote accessories, if attached, will function. If no test gas is available to conduct functional testing, remove cover and, while holding down the cover removal switch, blow smoke from a cotton wick or punk directly at the head to cause an alarm. The alarm indicator should illuminate within one minute.

Wire an SL-2000 to a remote annunciator

-For the MSR-100 Remote accessory wiring, use the following wiring connections: C+ to 20, T/R to 1, P+ to 2, AL+ to 11, C- to 19.
-For the MSR-50 Remote accessory wiring, use the following wiring connections: T/R to 1, P+ to 2, AL+ to 11, C- to 19.
-For MS series remotes, only wire for the features on your remote. For instance a remote with a key and red LED would only wire for those features. The following are the wiring contacts:
Red alarm LED- black wire to 19, red wire to 11
Buzzer- black wire to 19, red wire to 11
Green pilot LED- black wire to 19, red wire to 2
Key or pushbutton test and reset- 1 black wire to 1 and the other black wire to 20
Yellow trouble LED- black wire to 19, red wire to 4, and a jumper between 20 and 15
-For individual horns, strobes or horn and strobe combos, Wire the positive to 14, the negative to 19, and put a jumper between 13 and 20

Wiring for Electrical Contractors

Alarm contact terminals 16 and 6 (normally closed and common) can be used to break the red 24V power wire to the thermostat. 16 and 6 effectively works as a switch, in a normal condition 16 is connected to 6 and when in alarm 16 is disconnected from 6. Some residential furnaces have a fan rundown mode where the fan will run even after a signal from the thermostat, these furnaces sometimes have a DIL switch to program this feature or alternatively power can be broken to the furnace alternate to the thermostat by breaking the neutral power to the furnace through terminals 16 and 6.

Replacing the detector head

The ionization sensor is part number 55000-225APO and the Photoelectric sensor is part number 55000-328APO. To replace the sensor, remove the cover and twist the sensor to the left. Use the new sensor into the base twist to the right until it clicks into place.

Piolet LED will not turn on

Check power is good, probe across terminals 9 and 10, check for roughly 24V.
Check detector head is seated, rotate counterclockwise and reattach it by turning clockwise until it’s seated.
Check transparent lid, ensure it is fitted and not ajar and all screws are tightened, SW1 can be inspected for damage if the lid has been installed incorrectly previously.

How to mount the SL-2000

Duct smoke detectors can be mounted any way either vertically or horizontally if the sampling tube holes are facing the direction of airflow.

What size sampling tubes does an SL-2000 require?

NFPA72 recommends all sampling tubes to be at least 80% of the duct width i.e. if your duct is 12 inches wide, the sampling tube must be at least 9.6 inches long.

Test the SL-2000’s detector head sensitivity

Recommended procedure is removing detector head and running on external 24V power supply and detector base using an SDI Trutest 801 for testing sensitivity.

SL-2000 goes straight into alarm

If it’s an old installation, check the detector head and housing for excessive dust. Detectors can be blown out with compressed air or replacement detector heads ordered, 55000-328 for -P model or 55000-225 for the -N model.
If detector is interconnected to another detector in the system, this can be checked by looking to see if there are wires on terminals 1,12 and 20, check to see if the other detector is maybe in alarm.
If it’s a new installation, if detector has been wired to a remote or accessories remove wiring such that only power is connected, if it stops going into alarm confirm correct wiring for model of remote when reattaching and that key switch is not activated.
In some situations of high humidity or temperature swings such as in sunbelt states condensation can build up on and inside detectors which can cause false alarms, we recommend moving a detector further downstream on ductwork or inside building where temperature swings might not be as extreme.
If detector still goes into alarm when all wiring removed, replace detector head or RMA unit.
If 1 and 20 are attached to the fire panel for reset make sure it’s and open contact

Using an SL-2000 to shut down a residential furnace or commercial roof top unit

Alarm contact terminals 16 and 6 (normally closed and common) can be used to break the red 24V power wire to the thermostat.
16 and 6 effectively works as a switch, in a normal condition 16 is connected to 6 and when in alarm 16 is disconnected from 6.
Some residential furnaces have a fan rundown mode where the fan will run even after a signal from the thermostat, these furnaces sometimes have a DIL switch to program this feature or alternatively power can be broken to the furnace alternate to the thermostat by breaking the neutral power to the furnace through terminals 16 and 6.

SL-2000 catters when going into alarm

Breaking same power used to power detector when in alarm. Use a separate 24VAC transformer, power supply or mains power.

Can I use a System Sensor remote with an SL-2000?

Air product and controls duct smoke detectors are not compatible, or UL listed to work with System Sensor or other manufacturer’s remotes.

Connect an SL-2000 to a fire alarm control panel

SL2000 terminals 12 and 20 must be connected between all detectors desired to be interconnected, a common power source must be used such that all detectors interconnected must be powered from a common 24VAC transformer, or mains power circuit. Alarm Led will not light up but relays will click
For a common remote for common test/reset, 1 and 20 must be connected between all desired detectors. Alarm led will light up .

How to interconnect an SL-2000 for common alarm

SL2000 terminals 12 and 20 must be connected between all detectors desired to be interconnected, a common power source must be used such that all detectors interconnected must be powered from a common 24VAC transformer, or mains power circuit. Alarm Led will not light up but relays will click
For a common remote for common test/reset, 1 and 20 must be connected between all desired detectors. Alarm led will light up.

Connect a fire alarm control panel interface to remotely reset the SL-2000

Normally open and common relay contacts on the fire alarm interface can be connected to terminals 1 and 20 on the SL2000 duct smoke detector.

How to test and confirm correct install and operation of an SL-2000

Correct airflow can be confirmed with the use of a magnehelic differential pressure gauge between the sampling and exhaust tubes of the detector, a reading between 0.01 and 1.2 inches of water verifies enough airflow.

The detector head can be tested for correct operation by spraying TG-2000 test gas into the test port of the detector, an alarm would be expected. Continued testing also includes using the included test magnet on the top of the duct smoke detector housing between the 2 marked lines indicated on lid, again an alarm would be expected to confirm correct operation.

The detector control board and relays can be tested for correct operation by pressing the black test/reset button in the transparent lid hole, an alarm condition would verify correct operation (red LED on board).

How can I wire the SL-2000 and SL-701 series duct detector to shut down a fan or roof top unit?

Alarm contact terminals 16 and 6 (normally closed and common) can be used to break the red 24V power wire to the thermostat. 16 and 6 effectively works as a switch, in a normal condition 16 is connected to 6 and when in alarm 16 is disconnected from 6. Some residential furnaces have a fan rundown mode where the fan will run even after a signal from the thermostat, these furnaces sometimes have a DIL switch to program this feature or alternatively power can be broken to the furnace alternate to the thermostat by breaking the neutral power to the furnace through terminals 16 and 6.

How can I interconnect multiple SL-2000 series duct detectors for a global shutdown?

12 and 20 for global shutdown

How can I wire remote accessories to a SL-2000 series duct detector?

For the MSR-100 Remote accessory wiring, use the following wiring connections: C+ to 20, T/R to 1, P+ to 2, AL+ to 11, C- to 19.
For the MSR-50 Remote accessory wiring, use the following wiring connections: T/R to 1, P+ to 2, AL+ to 11, C- to 19.
For MS series remotes, only wire for the features on your remote. For instance a remote with a key and red LED would only wire for those features. The following are the wiring contacts:
Red alarm LED- black wire to 19, red wire to 11
Buzzer- black wire to 19, red wire to 11
Green pilot LED- black wire to 19, red wire to 2
Key or pushbutton test and reset- 1 black wire to 1 and the other black wire to 20
Yellow trouble LED- black wire to 19, red wire to 4, and a jumper between 20 and 15

How can I test the SL-2000 duct detector?

Correct airflow can be confirmed with the use of a magnehelic differential pressure gauge between the sampling and exhaust tubes of the detector, a reading between 0.01 and 1.2 inches of water verifies enough airflow.

The detector head can be tested for correct operation by spraying TG-2000 test gas into the test port of the detector, an alarm would be expected. Continued testing also includes using the included test magnet on the top of the duct smoke detector housing between the 2 marked lines indicated on lid, again an alarm would be expected to confirm correct operation.

The detector control board and relays can be tested for correct operation by pressing the black test/reset button in the transparent lid hole, an alarm condition would verify correct operation (red LED on board).

How can I clean the Sl-2000 detector head and the sample/exhaust tubes?

The best methods of cleaning are to vacuum the detector head thoroughly or to blow the detector head out using
clean, dry compressed air. Do not use chemicals or non-conforming air to clean the detector head housing as this could contaminate the detector head and damage the casing. Sensing tubes must be inspected and cleaned in to allow the free flow of air through both inlet and exhaust tubes.

Addressable vs conventional

Only some panel that handle Apollo Communication protocol can handle the addressable detectors, most cases are conventional detectors

What approvals does the SL-2000 hold?

UL, ULC, MEA

Remote shows trouble but detector does not have any indication lights

recheck the wiring on the remotes. If there is a green light on the detector that means there should be no trouble on the remotes