Features
- Light with Horn Mounted & Wired to Helios
- Single Lights Available in Red, Green, Yellow, Blue, or White
- Units with One of Five User Selectable Lights Available
- Units with Three Layered Lights Available
- Light / Horn Powered Directly from Helios
- Light / Horn / Reset Button Mounted and Pre-Wired to Helios
- Light / Horn Programmable for Variety of Reset Functions, Including:
- Silence Horn at Any Time
- Light Stays on Until Alarm Clears
- Light Can Be Wired to Flash (Not Available on MOD-PD2LH5CB1) or Stay Steady On
- IP 65 Rated
- 85 dB Horn
- Operates from -40 to 40°C (-40 to 104°F)
Overview

Helios Meter Shown with MOD-PD2LHRB1 Red Light / Horn and Reset Button. Meter Sold Separately.
The Helios can be provided with an optional light(s) with built-in 85 dB horn that comes mounted and wired to the instrument or as separate items to be mounted as the user desires. Meter is sold separately. The MOD-PD2LH Series is available in three different light configurations. The first option is a factory ordered Light / Horn with a color of either red, green, yellow, blue, or white. The second option is a Light / Horn the user determines the light color (red, green, yellow, blue or white) by connecting the appropriate wire. The third option is a Light / Horn with red, yellow, and green layers the user can turn on independently.
The MOD-PD2LH can be powered from the Helios’s 200 mA transmitter power supply with enough power left over to drive most transmitters.
The light(s) and horn can be controlled independently of each other via separate relays on the Helios. These relays can be programmed for automatic or manual reset action to satisfy a wide variety of audible and visual alarm applications. The light can be programmed to flash (not available on MOD-PD2LH5CB1) or stay steady-on.
The Light / Horn and Reset Button do not affect the Helios’s NEMA 4X rating, but do void its UL approval.
Note: The Light / Horn accessory is powered from the 200 mA transmitter power supply, so when this is installed, there is less power available for the transmitter. See Transmitter Power Supply specification for details.
Applications
There are a wide variety of ways these Light / Horn devices can be controlled by the Helios's four relays to satisfy visual and audible alarm applications. Please feel free to contact tech support to discuss your particular application. The following examples illustrate some typical applications.
MOD-PD2LH Models

Note: Unless otherwise specified, this MOD is shipped wired in the above fashion.
The MOD-PD2LH models are the simplest devices in the Series and are made up of a single-color light and horn. A typical way to use the MOD-PD2LH is to program the Helios so the horn can be silenced at any time via the Reset Button or F3 front panel button on the Helios, and light to reset automatically when the alarm clears:
Relay | Connected to | Default Reset |
1 | Flashing Light(1) | Auto reset |
2 | Horn | Silence with Reset Button |
3 | User Device | As user desires |
4 | User Device | As user desires |
1 Light can be wired to flash or stay steady on. |
MOD-PD2LH5CB1

Note: Unless otherwise specified, this MOD is shipped wired in the above fashion.
The MOD-PD2LH5CB1 shows one color at a time and the light color (red, green, yellow, blue or white) is determined by which wires are connected to power through the Helios's relays. A typical application for the MOD-PD2LH5CB1 might involve lighting up the red light to indicate low and high alarms using the Helios's four internal relays:
Relay | Purpose | Range | Light/Horn | Action |
1 | Low alarm | < 199 | Red light | Auto |
3 | Low alarm | < 199 | Horn | Latch |
2 | All OK | 200 to 500 | Green light | Auto |
2 | High alarm | > 500 | Red light | Auto |
4 | High alarm | > 500 | Horn | Latch |
MOD-PD2LH3LCB1-RYG

Note: Unless otherwise specified, this MOD is shipped wired in the above fashion.
The MOD-PD2LH3LCB1-RYG can light up red, yellow or green bands as determined by which wires are connected to power through the Helio's relays. A typical application for the MOD-PD2LH3LCB1-RYG (and the default factory setting) might involve lighting up the green light to indicate everything is OK, the yellow light to indicate a High warning, and the red light to indicate a High alarm. The Horn will also sound at both the Warning and High alarms and can be manually reset at any time with the front panel reset button:
Relay | Purpose | Range | Light/Horn | Action |
1 | All OK | < 199 | Green light | Auto |
2 | Warning | 200 to 500 | Yellow light | Auto |
3 | Warning | 200 to 500 | Horn | Latch |
2 | High alarm | > 500 | Red light | Auto |
4 | High alarm | > 500 | Horn | Latch |
Dimensions Units: Inches (mm)

Connections

MOD-PD2LH Models
Connections shown for a red light model. For other MOD-PD2LH models, the red wire is the color of the light. Connect the red and black wires for a Steady On light and red and gray wires for Flashing light.

MOD-PD2LH5CB1
Connect the LED color to the plus supply and the black wire to the minus supply to turn the LED on. Be aware of limitations for applications requiring different color lights for different alarm conditions.

MOD-PD2LH3LCB1-RYG
Connect the LED color to the plus supply for a Steady On light and LED color and gray wires to the plus supply for Flashing light. The black wire should be connected to the minus supply.
Wiring Connections for MOD-PD2LH Models
Wiring Connections for Transmitter Powered by Helios
The Helios can be wired to power both the Light / Horn accessory as well as the transmitter input and isolated 4-20 mA output as the following diagram illustrates.

Wiring Connections for Transmitter Powered by External Source
Transmitters and sensors that require more than 163 mA must be powered by an external power source, such as the PDA1024 as the following diagram illustrates.

Reset Button
The reset button can be used to silence the horn or turn off the light (9 labels provided).
Reset Button
9 Labels Provided