BOSCH D341 Air Duct Smoke Detector Housing Instruction Manual
- June 17, 2024
- Bosch
Table of Contents
BOSCH D341 Air Duct Smoke Detector Housing
Product Information
Specifications
- Product Name: D341/D342 Air Duct Smoke Detector Housing
- Compatible Detectors: D285DH Photoelectric Detectors, D286 Ionization Smoke Detectors
- Power Options: 24 VDC, 24 VAC, 120 VAC, 220 VAC, or 240 VAC
- Alarm and Trouble Relay Contacts for Control Panel Interface
- Auxiliary Form C Alarm Relay Contacts for Other Functions
Description
The D341/D342 Air Duct Smoke Detector Housings are designed to mount to HVAC system ducts to monitor the presence of smoke in theconditioned air. These housings work with compatible detectors for general property protection. The housing operates on various power options and provides alarm and trouble relay contacts for control panel interface.
Assembly Instructions
- Combine the desired sample tubes to achieve the desired length. For example, if you need a 7 ft sample tube, combine a 3 ft and a 5 ft sample tube. Cut 1 ft from the narrow end.
- Support sample tubes longer than 3 ft at the end opposite the duct detector. The support hole should be 1 in. to 2 in. below the entry hole to allow for possible moisture drainage.
- Seal the gap between the duct and sample tube.
Sample Tubes
A sample tube’s maximum length is 10 ft and its minimum length is 1 ft. It is important to have at least 12 sample holes within the duct. Do not cut sample tubes to less than 12 sample holes.
Product Usage Instructions
- Mount the D341/D342 Air Duct Smoke Detector Housing to the HVAC system duct using appropriate mounting brackets and hardware.
- Connect the compatible detector (D285DH or D286) to the housing.
- Provide power to the housing using one of the compatible power options (24 VDC, 24 VAC, 120 VAC, 220 VAC, or 240 VAC).
- Connect the alarm and trouble relay contacts to the control panel interface.
- If desired, connect the auxiliary Form C alarm relay contacts for additional functions such as fan shutdown.
- To test the system, place an external magnet on the detector housing or switch a signal from a remote test or indicator plate.
- To reset the system, shut down power and place a magnet on the detector housing, or send a signal from the remote test or indicator plate.
FAQ
- Q: What detectors are compatible with the D341/D342 Air Duct Smoke Detector Housing?
- A: The D341/D342 Air Duct Smoke Detector Housing is compatible with D285DH Photoelectric Detectors and D286 Ionization Smoke Detectors.
- Q: What power options are available for the D341/D342 Air Duct Smoke Detector Housing?
- A: The D341/D342 Air Duct Smoke Detector Housing operates on 24 VDC, 24 VAC, 120 VAC, 220 VAC, or 240 VAC.
- Q: Can I connect the D341/D342 Air Duct Smoke Detector Housing to a control panel?
- A: Yes, the housing provides alarm and trouble relay contacts for control panel interface.
- Q: Are there additional functions available with the D341/D342 Air Duct Smoke Detector Housing?
- A: Yes, there are two auxiliary Form C alarm relay contacts available for other functions such as fan shutdown.
Trademarks
The National Fire Alarm Code® is a registered trademark of the National Fire Alarm Association, Inc. Life Safety Code® is a registered trademark of the National Fire Alarm Association, Inc.
Overview
The D341/D342 Air Duct Smoke Detector Housings are designed to mount to heating, ventilation, and air conditioning (HVAC) system ducts to monitor the presence of smoke in the conditioned air. These housings work with D285DH Photoelectric Detectors andD286 Ionization Smoke Detectors (provided separately) for general property protection. The D341/D342 combines with an efficient housing design that samples the air passing through a duct and allows the detection of a potentially hazardous condition. When smoke is detected, the detector sends an alarm signal to the control panel that initiates thenecessary action to shut off fans and blowers or to change over to other air handling systems. The D341/D342 operates on 24 VDC, 24 VAC, 120 VAC, 220 VAC, or 240 VAC. Alarm and trouble relay contacts are provided for the control panel interface. In addition, two auxiliary Form “C” alarm relay contacts are available for other functions such as fan shutdown. Test the system by placing an external magnet on the detector housing or switching a signal from a remote test or indicator plate. Reset the system by shutting down power and placing a magnet on the detector housing, or by sending a signal from the remote test or indicator plate.
Install the D341/D342 according to
- NFPA 90A: Standard for the Installation of Air Conditioning and Ventilating Systems,
- NFPA 72: National Fire Alarm Code®, NFPA 101: Life Safety Code®, any applicable local and state codes, and your local authority having jurisdiction (AHJ).
Description
Table 1: Product Description
Types| D341: Air Duct Smoke Detector Housing for 24 VDC, 24 VAC, or 120 VAC
operation. This housing requires a detector head.
D342: Air Duct Smoke Detector Housing for 24 VDC, 24 VAC, or 220 VAC, or 240
VAC operation. This housing requires a
detector head.
Optional Equipment:| D285DH: Photoelectric smoke
detection head
D286: Ionization smoke detection
Head
D344-1.5: 1.5 ft (0.46 m) sample tube D344-3: 3 ft (0.9 m) sample tube D344-5: 5 ft (1.5 m) sample tube D344-RT: Remote test kit (D307)
D344-RL: Remote LED indicator kit
(D306)
D344-TF: Tube filters (20 per package)
for sample and exhaust tubes SMK-TM: Test magnet
DRA-5: Remote alarm indicator
EOL200: End-of-line (EOL) Module
Assembly
The D341/D342 includes:
- One housing, power card, and cover assembly
- Two #10-24 x 1 in. machine screws for mounting
- Two #10-24 jack nuts
- One exhaust tube
- Two tube clamps with four screws
- Two foam gaskets
- Two air filters
- One drilling template
- One cover gasket
The D341I/P and D342I/P also include a head and 1.5 ft (0.46 m) sample tube.
Sample Tubes
Sample tubes must extend across the width of the duct. These tubes are available in three sizes:
- D344-1.5 (1.5 ft [0.46 m])
- D344-3 (3 ft [0.91 m])
- D344-5 (5 ft [1.52 m])
Sample tubes include an end plug that must be installed in the narrow end (refer to Figure 1).
A sample tube’s maximum length is 10 ft (3.05 m); its minimum length is 1 ft (30.48 cm). You can join or cut sample tubes to make different lengths.
Sample tubes must have at least 12 sample holes within the duct. Do not cut sample tubes to less than 12 sample holes.
To create a new sample tube by combining two tubes:
- Remove the roll pin and set screw from one tube.
- Remove the end plug from the other tube.
- Push the flared end over the tube you want to lengthen.
- Align the air holes and insert the set screw.
- Reinstall the end plug.
For example, you need a 7 ft (2.13 m) sample tube. Combine a 3 ft (0.91 m) sample tube and a 5 ft (1.52 m) sample tube. Cut 1 ft (30.48 cm) from the narrow end. Sample tubes that are more than 3 ft (0.91 m) must be supported at the end opposite the duct detector. The support hole should be 1 in. to 2 in. (2.5 cm to 5 cm) below the entry hole to allow for possible moisture drainage (refer to Figure 2). Seal the gap between duct and sample tube.
You can remove a maximum of 6 in. (15 cm) from the D344-1.5 for 1 ft (0.30 m) duct installations. If using the D344-1.5 in installations where the duct width is between 12 in. (30.5 cm) and 18 in. (45.7 cm), cover some of the sample holes. There are 19 sample holes in the D344-1.5, but only 12 of them are needed for normal installation. Depending on the length, you might need to cover some of the holes with duct tape. Use even spacing when you cover sample holes. This allows for an even sample across the width of the duct (refer to Figure 3).
Mounting
Preparing the Duct
- Verify the duct air flow and velocity.
The D341/D342 is designed for use in air handling systems that have air velocities between 300 ft/min and 4000 ft/min (1.52 m/c to 20.3 m/c). Check the HVAC engineering specifications to ensure the air velocity in the duct falls within these parameters. If necessary, use a velocity meter to check the air velocity in the duct.
Selecting a Mounting Location
Avoid stratification and dead air space when taking a representative air
sample. These conditions can be caused by return duct openings, sharp turns,
connections, and long uninterrupted runs. Place the duct smoke detectors in a
range of six to ten times the width of the duct from any uninterrupted run.
Refer to Figure 4 for a typical duct detector placement
Placing the Housing
The D341/D342 can be mounted in any direction in 90° increments without regard
to air flow direction (refer to Figure 5).
- Locate the mounting template and remove it from its backing (refer to Figure 6).
- Place the mounting template over the desired location on the duct (refer to Figure 7).
- Drill out the required holes (two) and remove any remaining debris.
- Remove the template after the drilling is complete.
- Place a #10-24 jack nut in each of the two 3/8 in. (9.5 mm) holes (refer to Figure 8).
- Insert the #10-24 x 1 in. machine screws into the jack nuts and tighten the screws firmly. This attaches the jack nuts to the duct. You might need to hold the jack nuts with an installer wrench or a pair of pliers while tightening the screws. This stops the jack nut from spinning in the hole. Remove the screws and set them aside for later use.
Mounting Template
- 1-3/4 in. (44.5 mm) diameter sample tube holes (2)
- 3/8 in. (9.5 mm) diameter duct mounting holes (2)
Note: Remove the template after drilling
- Place the two foam gaskets over the sample and exhaust ports located on the back of the D341/D342 (refer to Figure 9).
- Mount the D341/D342 to the jack nuts in the duct using the #10-24 x 1 in. screws. Do not over tighten the screws. Over-tightening can cause excessive bowing of the duct (refer to Figure 10).
- Locate the sample and exhaust tubes. Ensure the sample tube has a plug installed at the narrow end of the assembly (refer to Figure 11).
- Note the direction of the airflow in the duct. Place the sample tube so the sampling holes face into the air flow (refer to Figure 12).
- Ensure the exhaust tube is downwind from the sample tube (refer to Figure 13).
- Insert the sample and exhaust tubes into the housing. The sample tube holes must face into the air flow. The alignment pins on the tubes must seat into the housing. Secure the tubes in place using the tube clamps provided (refer to Figure 14).
- Place the tube filters over the open ends of the sample and exhaust tubes (refer to Figure 15).
- Visually inspect the duct smoke detectors.
NFPA-72 requires a semi-annual visual inspection. Clean or replace the tube
filters during this inspection. Order part D344-TF for replacements as
needed.
Jumpers
The power card contains two jumpers:
- Tamper jumper that enables or disables the housing cover tamper switch.
- Reset jumper that enables or disables the remote key switch reset function. The power off reset functions normally regardless of the jumper setting. Figure 16 shows the location of the two jumpers on the power card. Figure 17 shows the enable and disable settings for the tamper and reset jumpers
Disable the reset jumper when not using the D344-RT.
Wiring
Figure 18 shows the wiring knockout holes in the smoke detector duct. Refer to
Figure 19 for the wiring terminals
Primary Power
- The D341 is designed for a primary power of 24 VAC, 120 VAC, or 24 VDC.
- The D342 is designed for a primary power of 220 VAC, 240 VAC, 24 VDC, or 24 VAC.
The D341/D342 is designed for one power source only. Do not connect a high- voltage AC source and a low-voltage AC/DC source to the same detector
Refer to Figure 20 for 120 VAC, 220 VAC, or 240 VAC wiring. Refer to Figure 21 for 24 VAC or 24 VDC wiring.
D344-RT Remote Test/Indicator
NFPA-72 requires detectors have remote alarm indicators where induct smoke detectors are installed in concealed locations that are more than 10 ft (3 m) above the finished floor. Remote alarm indicators are also required in arrangements where the detector’s alarm indicator is not visible to responding personnel. Do not exceed a distance of 500 ft (152 m) between the D307 and the D341/D342. Use #18 AWG (1.2 mm) wire or larger. Refer to Figure 22 for the D344-RT wiring.
D344-RL Remote Indicator
Do not exceed a distance of 500 ft (152 m) between the D306 and the D341/D342. Use #18 AWG (1.2 mm) wire or larger.
Refer to Figure 23 for the D344-RL wiring.
DRA-5 Remote Alarm Indicator
- Do not exceed a distance of 500 ft (152 m) between the DRA-5 and the D341/D342. Use #18 AWG (1.2 mm) wire or larger
Refer to Figure 24 for the DRA-5 wiring
D341/D342 to Control Panel
Refer to Figure 25 for the D341/D342 to control panel wiring
Multiple D341/D342s to Control Panel
Refer to Figure 26 for multiple D341/D342 to control panel wiring.
- D341/D342
- EOL resistor
- Control panel
- Alarm loop
D341/D342 to Control Panel
Refer to Figure 25 for the D341/D342 to control panel wiring.
- D341/D342
- EOL resistor
- Control panel
- Alarm loop
D341/D342 to Mux Point Module
Mount the small mux point modules inside the D341/D342 on the power card side. Refer to Figure 27 for the D341/D342 to mux point module wiring.
- D341/D342
- EOL resistor
- Zone
- FACP or mux point module
Single D341/D342 for Fan Control
Refer to Figure 28 for single D341/D342 to fan control wiring.
- Power control
- Fan control
- System control/thermostat
Testing
Verify air flow to ensure the system is operating properly. Use a manometer to verify the correct velocity pressure readings ranging 300 ft/min to 4000 ft/min (1.52 m/s to 20.3 m/s). Ensure the water pressure differential between the sampling tubes ranges from 0.01 in. (0.25 mm) to 1.8 in. (4.57 cm).
- Check the wiring from the control panel to the last D341/D342 on each run for proper polarity and continuity. Ensure each run terminates with an EOL resistor as specified by the control panel’s manufacturer.
- Apply power to the system and check for alarms.
- a. Note which smoke detectors are in alarm, if any, and shut down the system down.
- b. Remove these detectors from their duct housing and recheck the duct housing for proper wiring. If the problems persist, replace the affected smoke detectors or swap them with known good units. This determines if the problem is caused by the detector or the duct housing.
- c. If there is a system alarm with no detector alarms present, remove all smoke detectors and check the wiring at each duct housing. Pay close attention to the wiring of each EOL resistor
- When the system is free of alarms, check each detector to ensure the red LED indicator is flashing approximately every 4 sec for the D285DH and every 11 sec for the D286. This verifies the detector is receiving power and operating properly.
- Test each detector to ensure it will cause a control panel alarm. Reset the control panel after each test.
- Test the detectors by doing one of the following:
- a. Place a SMK-TM magnet against the duct housing’s test point notch located on the front cover (refer to Figure 29).
Figure 29: Testing the Detector
- SMK-TM magnet
- Test point notch
- Detector
- Duct housing
-
* a.When a detector alarms, the red LED indicator activates and latches in the ON position. Ensure you clear the alarm before proceeding to the next detector.- b. Reset the detector by momentarily removing power or by placing a magnet in the reset notch located near the rear of the housing (refer to Figure 30 on page 11).
- c. Test and reset duct detectors with the D344-RT installed by moving the keyswitch to the appropriate position and observing the Alarm LED.
- Check the overall loading of the alarm loop by measuring the voltage across each EOL resistor. This voltage should equal or exceed the minimum specified by the control panel’s manufacturer
Resetting the Detector
- SMK-TM magnet
- Test point notch
- Detector
- Duct housing
Maintenance
- NFPA-72 requires a semi-annual visual inspection of the duct smoke detectors. Clean or replace the tube filters during this inspection. Order part DS294-TF for replacements as needed.
- Notify all concerned parties before and after performing maintenance or testing on the fire alarm system.
At least once a year, clean the detector and base using a vacuum or clean/dry compressed air.
Specifications
Refer to Table 2 for the D341/D342 specifications
Bosch Security Systems, Inc.
130 Perinton Parkway Fairport, NY 14450-9199
- Customer Service: 800-289-0096
- Technical Support: 888-886-6189