RLE Technologies customers often want to use our SD-R01 spot detector to drive an external load, like an audible alarm or a pump. RLE does not currently have a leak detection product with a powered output. The SD-R01, like other RLE Technologies leak detection products, has a non-powered output: a Form C relay output.
The Form C relay output is essentially two switches, one closed or “on” during normal operation, and one open or “off” during normal operation. When a leak is detected, the normally closed (or NC) switch opens or turns “off,” and the normally open (or NO) switch closes or turns “on.”
The relay connection on the SD-RO1 and other RLE products consists of three terminals: one for the NC output, one for the NO output, and a common input (COM) for both sides.
If you want to signal a Normal condition by lighting a green LED and a Leak condition by lighting a red LED, attach the leads of the power source and LEDs to the SD-RO1 as follows:
- Attach the positive lead of a DC power source for the LEDs to the COM terminal.
- Attach the positive lead of the green LED to the NC terminal.
- Attach the positive lead of the red LED to the NO terminal.
After grounding the negative leads of the DC power source and the LEDs, the user has a simple red/green alarm circuit.
If you want to drive a load significantly larger than a pair of LEDs, you can attach a larger power source, AC or DC, to the COM terminal of the relay output. The SD-RO1 relay can handle up to 1 A @ 24 VDC, or 0.5A resistive @ 120 VAC. Check our product datasheets for other RLE product output ratings.