Mechanical Relay Modules Switch

Sept. 16, 2011
Opto 22's new SNAP-OMR6-A and SNAP-OMR6-C mechanical relay modules fill an important need for engineers, plant managers, technicians, and others seeking a cost-effective way to switch higher voltages and currents without the need for breakout boards, header cables, or other interposing hardware.

The new SNAP-OMR6-A and SNAP-OMR6-C power relay output modules offer four separate channels of switching for up to 250 VAC or 30 VDC, 6 amp loads. Significantly, the new modules are designed and built in the same form factor as Opto 22's standard SNAP I/O modules. As a result, the SNAP-OMR6-A and SNAP-OMR6-C offer three times the rated current switching capability of standard SNAP optically isolated outputs, and twelve times the rated current switching capability of SNAP reed relay modules-all in the same amount of rack space.

The features and capabilities of the two new mechanical relay modules address at least three important customer needs. First, their ability to independently switch up to 6 amps per channel helps cut costs by eliminating the need for additional hardware to switch the load. Second, they are ideal for applications with inrush currents and inductive, capacitive, or resistive loads. (In contrast, Opto 22's current mechanical reed relay modules-which offer a maximum of 0.5 amps switching current and 120 volt ratings-are better suited for very low-current applications like signal switching.) Finally, because the SNAP-OMR6-A and SNAP-OMR6-C are mechanical (not solid-state) relays, each is capable of switching either AC or DC power. This feature not only potentially reduces the number of modules needed for any given application, but also offers advantages for laboratory and testing applications where the polarity of the electrical circuit is subject to change.

Although the SNAP-OMR6-A and SNAP-OMR6-C both feature channel-to-channel isolation, the two modules also have distinct differences. The SNAP-OMR6-A is a Form A, Single Pole Single Throw (SPST) relay with contacts that are normally open. The SNAP-OMR6-C is a Form C, Single Pole Double Throw (SPDT) relay with mechanical contacts that can be wired as normally opened, normally closed, or both. Having these dual options allows users to effectively safeguard their control applications. For example, in the event that power is lost, the contacts on the SNAP-OMR6-C module will return to the position that's been designated as normal (open or closed), thus allowing an opportunity for connected equipment to operate (or shut down) safely.

The higher load capabilities of the SNAP-OMR6-A and SNAP-OMR6-C make them ideal for switching solenoids, compressors, motors, and contactors on heavy equipment used in the HVAC, refrigeration, oil and gas, and water and wastewater industries. The modules will also prove useful for energy managers, building owners, and others looking to switch equipment on and off as part of their demand-response and other energy management operations.

"The new SNAP-OMR6 modules are the first of their kind for us," says Opto 22 CEO Mark Engman. "They can handle more current than any other SNAP output modules, and that switching power is all built right in. Customers will be able to use these modules to power a very broad range of their AC and DC systems, devices, and machinery. "

The SNAP-OMR6-C and SNAP-OMR6-A are each priced at $92.00 USD and are available now from the Opto 22 website and a worldwide network of authorized distributors. For more information, contact Opto 22 Presales Support by calling 951-695-3000 or toll free 1-800-835-6786.

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