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Low-Signal Relay Output

A Low-Signal Relay Output is designed to switch low current loads, up to around 1A at 24VDC.

In all shipped SiteMonitor products to date, the low-signal relay outputs have been implemented using an Omron G5V-1 relay. If detailed specifications are needed, they can be obtained from the Relay's datasheet which can be downloaded here. The following is a brief summary of the specifications:

The primary purpose of a Low-Signal relay is to switch lower-current loads. As a result, the low-signal relay has been optimized to be able to switch loads as low as 1mA at 5V. Lower-current loads may not be able to "break through" any corrosion or other deformities which may occur as the relay ages. If your load is less than 1mA, then you should consider switching your load in a different way.

On the other end of the scale, the Low-Signal relay can also switch somewhat larger loads as well. To maximize the life of the contacts, the loads should be limited to 1A at 24VDC. The datasheet provides additional data for other voltages and currents, including a chart showing the relationship between the operating current and the service life. At 1A@24V, the expected service life is 10,000 operations. Reducing the switching current to 0.4A@24V will increase the expected service life to 200,000 operations. We do not recommend switching 125VAC as specified in the relay's datasheet, although it is possible to do so.

If you need to switch a load with a higher voltage and/or amperage than the low-signal relay is able to handle (and a relay output capable of higher current is not available), we recommend using the relay output to switch another, larger, relay which then controls the load. This is safer, and field-wired relays are generally easier to install in the event of a failure.