Much of your industrial equipment and motors use electromechanical relays. The relays control electric flow over a circuit to a starter or other component. They move electrical contacts so that they touch each other, completing the circuit, or away from each other, interrupting it. An electromechanical relay works in a DC unit or an AC unit at common voltages, a key benefit of the device. Because electromechanical differential relays are designed for specific applications, your company will need to collect information about electromechanical relays to make sure you are selecting the best type for the job. Among the things to know about your situation are the pole and throw specifications and mounting preference.

You'll find some electromechanical relay suppliers carry specific relay models, while others provide a variety of them. As your company investigates info about electromechanical relays, remember the following things:

1. There are several mounting choices for electromechanical counters.

2. Electromechanical relay models are designed for specific applications.

3. Various electromechanical relays offer different performance characteristics.

Action Steps
The best contacts and resources to help you get it done

Choose the electromechanical relay mounting that's best for your needs

Among the mounting choices for electromechanical relays are bracket or flange mount, DIN rail, socket or plug-in style and PC board. The main consideration for mounting style is accessibility for service and replacement. Determine the one that works best with your machinery and physical plant.

I recommend: Check the variety of electromechanical differential relays at Automationdirect.com, which includes cube, octal, solid-state and PC board models. Find a large inventory of electromagnetic relays at Teledyne Relays. It carries surface-mount and magnetic-latching models.

Find electromechanical relay distributors with the devices you want

The basic types of electromechanical relays are general-purpose, reed, heavy-duty, and military/aerospace. General-purpose relays control most small electrical devices. Reed relays control starter motors and solenoids. Heavy-duty, or motor control, relays also control starters as well as other industrial components. Military/aerospace relays perform the same tasks but require special certification. Determine the type your businesses needs and find a reliable supplier.

I recommend: Choose Magnecraft for power, solid state, time delay and several other relay models. Review the inventory at Deltrol Controls. Its relays include patented performance and alert technology.

Consider performance details in selecting an electromechanical counter

As your firm closes in on a selection, be sure to consider these performance specifications: operate time (or make time) and release time (or break time). These parameters tell how the device functions so your company knows what to expect. You can find specs at most supplier websites, or they will send you printed copies of the information.

I recommend: Check the general purpose plug-in relays and other models carried by Omron. It provides 2-D and 3-D sketches for each relay. Industry leader Siemens provides product details and configurations in addition to specs for all the relays it makes.

Tips & Tactics

Helpful advice for making the most of this Guide

• •  If your company supplies motors or equipment for military or aerospace use, you'll need to find electromechanical relay manufacturers that carry relays that meet MIL-SPEC or for aerospace certification.
• •  A number of other features apply to electromechanical relays, such as time delay, latching controls, visual readouts and push-to-test buttons.
• •  Temperature is an important operating parameter for an electromechanical differential relay. Make sure the one your firm chooses has been tested at the temperatures you expect.