The Wisualarm DHI-HY-SA5MA is a mains-powered photoelectric smoke alarm that draws its primary power from a permanent 230V mains connection and backs this up with a 10-year rechargeable lithium battery, removing the ongoing cost and hassle of replacing a standby battery over the alarm's working life. It suits general residential rooms — living rooms, bedrooms, hallways and landings — wherever early smoke detection is needed.
The alarm's 85dB(A) sounder gives clear audible warning alongside a visual LED indicator, and it interconnects by wire with up to 24 other Wisualarm mains-powered smoke and heat alarms, so one triggered unit sounds every linked alarm across the property. Test and silence functions are supported via any working infrared remote control, useful for ceiling-mounted units out of easy reach.
Photoelectric
Sensor Type
≥85dB
Alarm Volume @ 3m
10-Yr
Lithium Battery Back-up
24
Max Interconnected Units
Grade D1
BS 5839-6 Classification
Mains + Backup
Power Supply
Grade D1 — Sealed Rechargeable Back-up
With its non-replaceable 10-year rechargeable lithium battery providing standby power, the SA5MA is classified as a Grade D1 device under BS 5839-6. This eliminates the battery-replacement obligation that applies to Grade D2 alarms, making it well suited to new-build and long-term rental properties where minimal maintenance is a priority.
Wired by Default, Wireless-Ready
The SA5MA interconnects over its own dedicated wiring with other Wisualarm mains-powered smoke and heat alarms as standard. Fitting the optional DHI-HY-MRF50-R8 wireless module lets it also join a WisuLink 868MHz wireless network, useful where running new interconnect cable to every room isn't practical during a retrofit.
Photoelectric Smoke Detection — Not for Kitchens
This is a smoke alarm, not a heat alarm, so it should not be fitted in kitchens or other rooms prone to cooking fumes and steam, which can trigger false alarms. For those spaces, use a Wisualarm heat alarm such as the HT5MA or HT5MB instead.
10-Year Rechargeable Battery
A sealed rechargeable lithium battery provides standby power for the alarm's full 10-year service life, with no battery changes required.
Photoelectric Smoke Sensing
A photoelectric sensing chamber gives fast, reliable detection of visible smoke while resisting many of the nuisance triggers that affect other detection types.
Hardwired Interconnect, 24 Units
Connects to up to 24 other mains-powered Wisualarm smoke and heat alarms over standard interconnect wiring, so one triggered alarm sounds every linked unit in the property.
Optional Wireless Expansion
Adding the DHI-HY-MRF50-R8 module lets this alarm also communicate over the 868MHz WisuLink wireless mesh, bridging wired and wireless zones in the same system.
IR Remote Test & Silence
Supports test and 9-minute silence functions via any working infrared remote control, letting installers and occupants manage the alarm from floor level rather than a ceiling-mounted button.
Clear LED Status Reporting
A green/red LED indicator reports standby and alarm conditions at a glance, so status is clear without needing to open the unit.
Up to 24 units via optional DHI-HY-MRF50-R8 WisuLink module
Installation
Installation
Ceiling mount
Does this alarm need its battery replaced?
No. The SA5MA uses a sealed 10-year rechargeable lithium battery that is not user-replaceable and is designed to last the alarm's full service life, provided it remains powered from the mains between any outages.
How many alarms can be linked together?
Up to 24 Wisualarm mains-powered smoke and heat alarms can be hardwired together on the interconnect line, so that any single alarm triggering sounds every linked unit in the property.
Is this alarm suitable for a kitchen?
No. This is a photoelectric smoke alarm, and cooking fumes and steam can trigger false alarms. Fit a Wisualarm heat alarm, such as the HT5MA or HT5MB, in kitchens and similar spaces instead.
Can this alarm work with wireless Wisualarm devices?
Yes, if fitted with the optional DHI-HY-MRF50-R8 wireless interconnect module, which lets the SA5MA join the 868MHz WisuLink mesh alongside battery-powered wireless alarms.
What's the difference between the SA5MA and SA5MB?
Both are mains-powered photoelectric smoke alarms with the same 24-unit interconnect capability. The SA5MA uses a sealed 10-year rechargeable lithium battery (Grade D1), while the SA5MB uses a replaceable 9V alkaline battery (Grade D2).
BTU & WATT Calculator
Room Dimensions
Room Type
Living Room
Bedroom
Kitchen
Bathroom
Conservatory
Hallway
Glazing Type
Single Glazed
Double Glazed
Triple Glazed
External Walls
0 Wall
1 Wall
2 Walls
3 Walls
4 Walls
Insulation Level
Poor
Average
Good (New Build)
Required Heating
0
Watts
0
BTUs
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