P2RLED vs P2RHK-120: Which Fire Alarm Notification Device Do You Need?
P2RLED vs P2RHK-120 comes down to the job site.
The P2RLED is usually the better pick for indoor 24V wall horn strobe needs.
The P2RHK-120 is usually the better pick for outdoor 120VAC high-candela horn strobe needs.
Both devices are fire alarm notification appliances. Both give sound and light during an alarm. But they are not the same device.
They do not serve the same use case. If you order the wrong one, it may not match the voltage, location, candela needed, or mounting setup.
Quick Summary
- Choose P2RLED for most indoor wall-mount horn strobe needs.
- Choose P2RHK-120 for outdoor 120VAC high-candela horn strobe needs.
- P2RLED uses LED strobe tech and is part of the L-Series LED line.
- P2RHK-120 is an outdoor SpectrAlert Advance horn strobe.
- P2RLED offers lower current draw with LED technology.
- P2RHK-120 includes a weatherproof back box and outdoor rating.
- Always match the device to the panel, voltage, plans, and local code.
Main Differences Between P2RLED and P2RHK-120
The main difference is use case: P2RLED is an indoor 24V LED horn strobe, while P2RHK-120 is an outdoor 120VAC high-candela horn strobe.
The P2RLED is part of the System Sensor L-Series LED indoor horn strobe line. The product data sheet lists LED technology, lower current draw, DVM test points, and field-selectable candela settings for wall units.
The P2RHK-120 is a System Sensor SpectrAlert Advance outdoor 120V horn strobe. Its datasheet lists regulated 120VAC operation, outdoor use, high-candela settings, and a weatherproof back box.
Use P2RLED for indoor 24V fire alarm notification jobs. Use P2RHK-120 for outdoor 120V high-output jobs.
What Is the P2RLED?
The P2RLED is a red, wall-mount, 2-wire horn strobe that uses LED strobe technology.
This device is made for indoor fire alarm notification. It gives both sound and flashing light. That means it can warn people with a horn and a strobe at the same time.
The P2RLED is a good fit when the job needs:
- Indoor wall mounting
- Red housing
- FIRE marking
- Horn and strobe in one device
- 24V notification appliance circuit use
- Lower current draw
- Field-selectable candela options
The L-Series LED data sheet states that wall units have field-selectable candela settings of 15, 30, 75, 95, 110, 135, and 185. It also notes LED technology for lower current draw.
That lower current draw can matter a lot. It may help on jobs where the NAC load is tight. It may also help when a system has multiple notification devices on a single circuit.
What Is the P2RHK-120?
The P2RHK-120 is a red outdoor horn strobe that operates on a regulated 120 VAC supply.
This device is made for outdoor fire alarm notification. It is not just a basic indoor horn strobe with a box added. It is meant for tougher spaces.
The P2RHK-120 is a good fit when the job needs:
- Outdoor installation
- 120VAC operation
- High candela output
- Weatherproof back box
- Red housing
- Horn and strobe in one unit
- Strong visible signal for outdoor areas
The P2RHK-120 data sheet lists field-selectable candela settings of 135, 150, 177, and 185. It also lists an outdoor temperature range from -40°F to 151°F and a rainproof NEMA 3R rating.
That makes it a better match for exterior walls, loading areas, yard spaces, outdoor exits, and other exposed areas where the plans call for this device style.
P2RLED for Indoor 24V Notification Jobs
Use P2RLED for indoor 24V horn strobes.
It fits most common indoor spaces: offices, hallways, schools, retail, medical offices, apartments, and storage rooms.
It’s not a one-size-fits-all fix. Always check the panel, voltage, candela setting, and mounting box first.
The LED design uses less power than older xenon strobes, which helps when upgrading old devices or planning a new system.
P2RHK-120 for Outdoor 120VAC High-Candela Needs
Use P2RHK-120 for high-brightness outdoor 120VAC horn strobes.
It is suitable for outdoor locations: exterior walls, loading docks, exits, parking areas, industrial sites, and equipment yards.
It comes with a weatherproof back box and offers high candela settings (135, 150, 177, 185).
Pick this part only when the job specifically needs outdoor use, 120VAC power, and strong visual output; not just because you need a loud strobe.
Do Not Mix Up 24V and 120VAC Devices
A 24V horn strobe and a 120VAC horn strobe are not the same.
This is one of the biggest buying mistakes. If the system needs 24V, do not order a 120VAC device. If the job calls for 120VAC, do not order a 24V device.
The voltage must match the system design. It must also match the power source and circuit shown on the plans.
Before you buy, check:
- The fire alarm drawings
- The device schedule
- The panel or power supply label
- The old device label
- The model number on the quote
- The installation guide
If you only compare the red faceplate, you can quickly order the wrong device.
Check Indoor vs Outdoor Rating Before You Order
Indoor and outdoor fire alarm devices have different jobs.
An indoor device should not be used outside unless it is listed for that use. Outdoor areas bring rain, heat, cold, dust, and moisture. A device must be rated for that space.
The P2RHK-120 data sheet lists outdoor use and rainproof details. The P2RLED data sheet focuses on indoor L-Series LED horn strobes and strobes.
Ask this before buying:
- Will the device be inside or outside?
- Will it be near water or weather?
- Does the plan call for NEMA-rated equipment?
- Does the device need a weatherproof back box?
- Is the wall exposed to sun, rain, or cold?
If the device is going outside, I would not guess. I would match the exact model listed for outdoor use.
Candela Matters More Than Many Buyers Think
Candela tells you how bright the strobe is.
A lower candela device may work for small indoor spaces. A higher candela device may be needed for large rooms, tall spaces, outdoor areas, or special layouts.
P2RLED wall units have a wide candela range, including lower settings such as 15 and 30 and higher settings up to 185. P2RHK-120 focuses on high-candela settings ranging from 135 to 185.
This matters because the fire alarm design may require a set candela level. If you install the wrong output, the device may not meet the plan.
Do not pick candela by eye. Check the drawings, code needs, and device schedule.
Common Ordering Mistakes to Avoid
The most common mistake is buying by photo rather than by model number.
P2RLED and P2RHK-120 can both appear as red horn strobes, but their details differ significantly. A photo cannot tell you the full story.
Avoid these mistakes:
- Ordering the wrong voltage
- Using an indoor device outside
- Ignoring candela settings
- Skipping the device schedule
- Matching only the color
- Assuming all horn strobes work the same
- Missing the mounting box or plate
- Replacing old parts without checking the full model number
I like to match fire alarm parts by model number first, then by voltage, then by location, then by candela. That simple order prevents many bad orders.
The Right Device Keeps the Job Moving
P2RLED and P2RHK-120 are both useful fire alarm notification devices, but they are built for different needs.
P2RLED is the better fit for many indoor 24V wall horn strobe jobs. P2RHK-120 is the better fit for outdoor 120VAC high-candela horn strobe jobs.
The safest choice is the one that matches the plans, voltage, location, and candela need. Do not buy based on looks alone.
Match the model number and system details first. That is how you order the right fire alarm notification device the first time.