Y902 — Modular Multi-Point Wireless Alarm System Specification

Contents

1. Overview
2. Ordering Information
3. Key Features
4. Technical Specifications
5. Related Products and Power Options
6. Interfaces and Indicators
7. Important Notes

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1. Overview

Y902 is a modular multi-point wireless alarm system with an internal rechargeable battery. A site can combine alarm units, trigger units, and LoRa repeaters as needed:

• An alarm unit combines a latching illuminated button, wireless linkage controller, audible-visual alarm, and internal rechargeable lithium battery.
• A trigger unit combines the latching illuminated button, wireless linkage controller, and internal battery without an audible-visual alarm.
• A LoRa repeater forwards Y902-L node status without a trigger button or audible-visual alarm.

Pressing the button on any alarm or trigger unit synchronizes the trigger state to the other nodes in the same Y902 network. Every alarm unit then activates its audible-visual alarm. The alarm stops only after all triggered buttons have been reset.

Y902 uses an external 24 V DC supply and charges its internal battery automatically. The external supply can come from a standard adapter or an optional solar power system. A change in the external power source does not change the Y902 model or hardware. If the external supply fails, the internal battery automatically maintains wireless communication, button triggering, and alarm operation.

Trigger and Button Indication

Press the built-in latching illuminated button once to hold the trigger state and turn on the button light. Press it again to release the button, clear the local trigger, and turn off the light. The button light shows only that unit's local trigger state; it does not show the network-wide alarm state.

Y902 does not expose an external DI to the user and does not accept remote alarm-trigger commands from the platform.

Network Architecture

• Y902-L uses LoRa multi-node automatic relay networking. The standard open-area range is 5 km, with an optional 10 km version.
• Y902-G synchronizes node trigger states through the existing 4G platform or server. It does not use LoRa automatic relay networking.
• Y902 and Y901 form separate networks and cannot share nodes.

Typical Applications

• Sites that require trigger points and alarm-output points in different locations
• Distributed alarm points in factories, warehouses, pump rooms, and equipment rooms
• Tunnels, underpasses, and utility corridors
• Locations that must retain alarm capability after external power loss
• Deployments that need more trigger points without an audible-visual alarm at every point

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2. Ordering Information

Model Code

Y902-C-F
 │   │ └── F: Module function (A / T / R)
 │   └──── C: Communication (G / L)
 └──────── Y902 series

Models

Model	Communication	Module Type	Description
Y902-G-A	4G	Alarm unit	Local trigger plus audible-visual alarm output
Y902-G-T	4G	Trigger unit	Local trigger without alarm output
Y902-L-A	LoRa	Alarm unit	Local trigger, LoRa linkage, and audible-visual alarm output
Y902-L-T	LoRa	Trigger unit	Local trigger and LoRa linkage without alarm output
Y902-L-R	LoRa	Repeater	Same base configuration as Y902-L-T, but without a trigger button; forwards LoRa data only

Suffixes

Suffix	Meaning
-G	4G communication through the existing platform or server
-L	LoRa communication with multi-node automatic relay networking
-A	Alarm unit with an audible-visual alarm
-T	Trigger unit without an alarm output
-R	LoRa repeater without a trigger button or alarm output

Package Contents

Quantity	Item
1	Ordered Y902 alarm unit, trigger unit, or repeater
1	Antenna for the communication version
1 set	Installation accessories

Order alarm units, trigger units, and repeaters in the quantities required by the site design. Y902-L-R repeaters and solar power systems are separate order items. The solar power system is an accessory and has no separate Y902 model suffix.

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3. Key Features

1. Modular deployment: Combine alarm units, trigger units, and repeaters for the required site layout.
2. Any-node trigger: A trigger at any alarm or trigger unit activates every alarm unit in the network.
3. LoRa automatic relay: Y902-L provides a standard 5 km open-area range and an optional 10 km version.
4. 4G linkage: Y902-G synchronizes node trigger states through the existing platform or server.
5. Latching illuminated button: Press once to trigger and again to reset; the light shows the local trigger state.
6. Internal backup battery: A built-in 5300 mAh rechargeable lithium battery automatically takes over after external power loss.
7. Guaranteed backup operation: At least 6 hours online after power loss; an alarm unit can provide at least 30 minutes of continuous audible-visual alarming during that period.
8. Continuous external supply: External 24 V DC powers the unit and charges the internal battery.
9. Alarm component: The alarm unit uses a Hosiden Besson Banshee Excel Lite 90020R5, rated up to 110 dB @ 1 m.
10. Manual network reset: Every triggered button must be reset before the network-wide alarm stops.
11. Optional LoRa repeater: Add a repeater where terrain, obstructions, or link length affect communication.
12. Optional solar supply: A solar system can replace the standard adapter at sites without utility power.

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4. Technical Specifications

Communication

Parameter	Specification
Communication	4G or LoRa
Communication suffix	-G or -L
Y902-G architecture	Node-state linkage through the existing 4G platform or server
Y902-L architecture	LoRa multi-node automatic relay networking
LoRa range	Standard 5 km in an open area; optional 10 km version
Product interoperability	Y901 and Y902 form separate networks and cannot share nodes
Remote command	Platform remote triggering is not supported; 4G services synchronize node trigger states only

Electrical and Control

Parameter	Specification
External supply	24 V DC
Trigger	Built-in latching illuminated button; press once to trigger and again to reset
Input type	Internal dry-contact input; no external DI exposed to the user
Linkage logic	Any triggered node activates all alarm units
Reset logic	The alarm stops after all triggered buttons have been reset
Alarm-unit output	Audible-visual alarm
Trigger-unit output	No alarm output
Typical LoRa control-unit current	30 mA @ 12 V DC; 15 mA @ 24 V DC, measured average
4G control-unit current	Depends on network conditions; confirm from the delivered configuration and test results

The LoRa current values exclude the audible-visual alarm, button light, charging circuit, and other power components. Do not use them as the complete-unit current.

Internal Battery

Parameter	Specification
Battery	Built-in rechargeable lithium battery pack
Capacity	5300 mAh
Charging	Automatic while external 24 V DC is present
Backup operation	At least 6 hours after external power loss
Alarm guarantee	A -A alarm unit can alarm continuously for at least 30 minutes during the six-hour backup period
User maintenance	The battery remains installed during normal use

Alarm Component

Parameter	Specification
Model	Hosiden Besson Banshee Excel Lite 90020R5
Maximum sound output	110 dB @ 1 m
Flash rate	1 Hz
Tone and volume	32 tones and 3 volume levels; factory-set and not exposed for field adjustment
Component temperature	-20 to +70°C
Component ingress protection	IP66 when installed with the specified deep base

Alarm-component ratings and approvals do not apply automatically to the complete Y902 assembly. Confirm complete-unit ratings from final validation documents.

Complete-Unit Construction

Parameter	Specification
Product form	Modular alarm system with alarm units, trigger units, and optional repeaters
Mounting	To be confirmed for the delivered enclosure
Dimensions	To be confirmed for the delivered enclosure
Complete-unit ingress protection	To be confirmed by complete-unit validation
Complete-unit operating temperature	To be confirmed by complete-unit validation

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5. Related Products and Power Options

Item	Applicable Version	Purpose	Boundary
Y902-L-R LoRa repeater	Y902-L	Receives and forwards Y902-L node states in obstructed or extended links	Based on Y902-L-T, but without a trigger button or audible-visual alarm
Solar power system	Y902-L-T / Y902-L-R	Replaces the standard adapter and supplies external 24 V DC at sites without utility power	External accessory; does not change the Y902 model, hardware, or internal battery

LoRa Repeater

• Y902-L-R joins the assigned Y902-L network and forwards status only within that network.
• Its communication, supply, internal battery, and enclosure are based on Y902-L-T; the latching trigger button is omitted.
• It does not create a local trigger state or provide an audible-visual alarm.
• A repeater improves the actual communication path. Do not add nominal ranges together as a coverage guarantee.
• Select the installation point from terrain, obstructions, antenna height, and on-site wireless tests.

Solar Power System

• The solar system supplies external 24 V DC and charges the Y902 internal battery.
• The V1 standard solar design supports one Y902-L-T trigger unit or one Y902-L-R repeater.
• The standard configuration includes an 80 W solar panel, off-grid charge controller, 24 V / 40 Ah external NMC lithium battery, and regulated 24 V DC output.
• The design condition assumes at least three peak-sun hours per day in the worst month and up to three consecutive days without solar input.
• The external battery provides long-duration off-grid energy. The internal 5300 mAh battery remains a device-level backup.
• The external battery requires a BMS with overcharge, overdischarge, overcurrent, short-circuit, and temperature protection. The controller charging profile must match the selected battery.
• 24 V is the regulated system-output specification. Actual battery operating and charging voltages follow the selected battery pack.

The measured LoRa control-unit load is approximately 0.36 W, or 8.64 Wh/day:

0.36 W × 24 h = 8.64 Wh/day

The V1 design adds a 25% load margin and assumes 70% total effective efficiency across the solar panel, controller, wiring, and conversion path. The standard product does not use the theoretical minimum panel size; it uses an 80 W panel.

For three days without solar input, the calculated storage floor is approximately 45 Wh:

10.8 Wh/day × 3 days ÷ (80% usable depth × 90% conversion efficiency) ≈ 45 Wh

The standard 24 V / 40 Ah external battery provides about 960 Wh at nominal voltage and supplies the main off-grid reserve. Recalculate panel and storage capacity when the site has fewer than three peak-sun hours in the worst month, more than three consecutive sunless days, shading, or additional loads.

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6. Interfaces and Indicators

Interface or Component	Description
Antenna	Supplied for the selected 4G or LoRa version
Power input	24 V DC from an adapter or solar system; charges the internal battery
Latching illuminated button	The only user trigger; press once to hold and again to reset
Button light	Shows only the local button's trigger state
Audible-visual alarm	Installed only on -A alarm units; responds to trigger states in the same Y902 network
Internal battery	Takes over automatically after external power loss
Solar external storage	Optional 24 V / 40 Ah NMC lithium battery supplies continuous external 24 V DC

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7. Important Notes

1. Module type: -A identifies an alarm unit, -T a trigger unit, and -R a LoRa repeater.
2. Alarm retention: The network-wide alarm remains active while any alarm or trigger unit stays triggered.
3. 4G linkage: Y902-G synchronizes node states through the existing platform or server and does not accept platform remote-trigger commands.
4. LoRa linkage: Y902-L supports automatic relay networking, with a standard 5 km open-area range and optional 10 km version.
5. Network separation: Y901 and Y902 nodes cannot join the same network.
6. Input boundary: Y902 uses only its built-in latching illuminated button and exposes no external DI.
7. Button-light boundary: The light shows only the local trigger state.
8. Backup guarantee: The internal battery provides at least 6 hours of operation after external 24 V DC fails.
9. Alarm guarantee: A -A unit can provide at least 30 minutes of continuous alarming during the six-hour backup period.
10. Complete-unit ratings: Do not apply the alarm component's IP66 or approvals to the complete Y902 assembly.
11. Safety boundary: Y902 supports auxiliary alarming and personnel notification. It must not serve as the only emergency-stop, life-safety, or hard real-time safety circuit.
12. Repeater boundary: Y902-L-R forwards LoRa status and has no trigger button or audible-visual alarm.
13. Solar boundary: The solar system is an external accessory with no separate model suffix. It does not change the Y902 hardware or internal battery.
14. Delivered configuration: Confirm complete-unit dimensions, mounting, ingress protection, and operating temperature from final validation documents.

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• Manufacturer: Hunan YenGear Tech Co., Ltd.
• Address: Room 21014, Building 1, Fudi Xingguang Tiandi, Yingxin Road, Yuhua District, Changsha, Hunan, China
• Email: hi@yengear.com
• Website: www.yengear.com