Rolling Shutter Alarm Sensor: Wired vs Wireless and Where to Fit It
Short answer: a rolling shutter sensor is a heavy magnetic contact that tells your alarm when the shutter is lifted. If your alarm panel is wireless, use the SH-43 (₹1,200) or the PLG-43 plunger sensor (₹1,449). If you run cable to a wired alarm zone, use the SH-WD (₹600) or the heavy-duty SH-3WD (₹849). If you have no alarm panel at all, the SH-AL (₹2,199) is a self-contained shutter alarm with its own siren. Fit the sensor inside the shop at the bottom of the shutter, where the slat meets the floor.
The shutter is the first thing a thief attacks in most Indian shops, godowns and garages, and a normal door contact is not built for it: the gap is wider, the metal flexes and the shutter takes a beating every day. This guide explains how shutter sensors work, how to choose between wired and wireless, and exactly where to fit one.
How does a rolling shutter sensor work?
Most shutter sensors are magnetic contacts in a strong housing. One part is fixed to the floor and the other to the bottom slat of the shutter. While the shutter is down, the two parts sit close together and the circuit stays normal. When someone lifts the shutter, the gap opens and the sensor signals the alarm. Our combo listing for the SH-43 says the alarm is sent when the shutter is forced open by just 2 to 3 cm, so the siren starts before anyone can crawl under.
A plunger sensor such as the PLG-43 works like a push switch in a box: the closed shutter or door keeps it pressed, and lifting the shutter releases it. It suits places where a floor magnet is hard to align.
Wired or wireless: which shutter sensor should you choose?
| Wireless (SH-43, PLG-43) | Wired (SH-WD, SH-3WD) | |
|---|---|---|
| Connects to | A wireless alarm panel by radio (PLG-43 is listed at 433 MHz) | A wired zone on an alarm panel or controller, by cable |
| Power | Battery inside the sensor | No battery; powered through the alarm circuit |
| Installation | Quick; no cable to route | Needs cable from the shutter to the panel |
| Upkeep | Replace the battery when the panel or app warns | Check the cable for damage |
| Best for | Existing shops, rented premises, ACJ panels | New fit-outs, wired panels, shutters far from the panel |
| Price on our store | ₹1,200 to ₹1,449 | ₹600 to ₹849 |
For one or two shutters, wireless is usually the quicker choice: you can fit it in an afternoon without breaking plaster. Wired sensors make sense when you are already laying cable, or when the shutter is far from the panel and you do not want to depend on radio range.
Shutter sensors on our store
| Sensor | Type | What the listing says | Price |
|---|---|---|---|
| SH-43 | Wireless | Made for rolling metal doors and shutters, battery powered, tamper detection | ₹1,200 |
| PLG-43 | Wireless plunger | 433 MHz box-body sensor for shutters, doors and windows; a combo listing gives up to 150 m in open areas | ₹1,449 |
| SH-WD | Wired | Detects opening and closing of rolling shutters; wired link for a stable connection | ₹600 |
| SH-3WD | Wired, heavy duty | 3 wires (NO and NC), over 40 mm operating gap, metal housing, 15-inch stainless steel armoured cable | ₹849 |
| SH-AL | Standalone alarm | Built-in alarm, volume 65 to 120 dB, runs on 2 AAA batteries (over 1 year), remote arm/disarm, takes up to 18 extra 433 MHz detectors | ₹2,199 |
Where should you fit a shutter sensor?
- Fit it inside. Mount the sensor on the inside of the shutter so it cannot be seen or pulled off from the street.
- Use the bottom slat. Fix the moving part to the bottom slat and the fixed part to the floor directly below, so the first few centimetres of lift break the contact.
- Pick the middle or the lock side. Thieves often bend a corner or cut the lock side. A sensor near the centre or the lock still sees the slat move when one corner is pried up.
- Mind the gap. Keep the two parts within the gap the sensor is made for. The SH-3WD allows over 40 mm, which helps on uneven floors and shutters that do not sit perfectly flat.
- Protect the cable. On wired sensors, run the cable along the wall in conduit. The SH-3WD comes with an armoured lead for the exposed part near the floor.
- One sensor per shutter. Every shutter is a separate way in, including the back godown shutter.
- Test it. Arm the alarm, lift the shutter a few centimetres and confirm the siren and phone alert. Repeat every month.
Which setup suits your shop?
- You want phone calls and SMS when the shutter opens: an ACJ panel with a shutter sensor. Combo-CN186 (ACJ-400 + PLG-43, ₹6,450), Combo-CN305 (ACJ-400 + SH-43, ₹6,999) or Combo-CN291 (ACJ-407 + SH-43, ₹8,999). Our ACJ panel comparison helps you pick.
- You want app alerts on Wi-Fi with a loud siren, no panel: Combo-CN284 (₹5,199) pairs the SRN-TY Tuya Wi-Fi siren, rated 120 dB, with an SH-43, and Combo-CN267 (₹5,350) uses a PLG-43. The listing notes that SMS and phone alerts on these need a paid service; the app alarm works on Wi-Fi.
- You just want a loud alarm on one shutter: the SH-AL (₹2,199). It sounds its own siren and you arm it by remote.
- You already have a compatible 433 MHz panel and want an outdoor siren too: the solar siren kit with SH-43 (₹4,749) adds an SRSOL-43 solar outdoor siren and 2 remotes. Confirm your panel's frequency and protocol before ordering.
For the rest of the shop, such as the cash counter, glass front and back door, work through our shop and showroom security checklist. See every sensor in shutter and vibration sensors, or plan the full system in the Security System Builder.
FAQ
Can I use a normal door sensor on a rolling shutter?
It is not a good idea. A shutter flexes, sits unevenly and has a wider gap than a door, so use a sensor made for shutters such as the SH-43, PLG-43, SH-WD or SH-3WD.
How much does a rolling shutter sensor cost?
On our store a wired shutter sensor costs ₹600 to ₹849 and a wireless one ₹1,200 to ₹1,449. A standalone shutter alarm with its own siren costs ₹2,199.
Will a shutter sensor work without an alarm panel?
The SH-43, PLG-43, SH-WD and SH-3WD need a panel or Wi-Fi siren to raise the alarm. The SH-AL has its own built-in siren and works alone.
How do I get a phone alert when my shop shutter opens?
Pair a shutter sensor with a Wi-Fi + GSM alarm panel such as the ACJ-400. The Combo-CN305 (₹6,999) gives you both in one box.
Which shutter sensor works with the ACJ-400?
We sell the ACJ-400 in ready combos with the SH-43 (Combo-CN305) and the PLG-43 (Combo-CN186), so both are known pairings.
Do I need one sensor for each shutter?
Yes. Each shutter is a separate entry point, so give each its own sensor and name it in the app or panel so you know which one opened.
Prices are NavKar Systems website prices on 27 October 2026, inclusive of GST, and may change.
