How to Select a Relay or Contactor

In the most basic terms a relay is remotely operated switch designed to isolate voltage and a contactor is a remotely operated switch designed to switch power. In everyday applications there is cross over and no clearly defined difference between a relay and a contactor. GIGAVAC relays and contactors have different design characteristics but both have the advantage of being sealed providing a safe and predictable switching environment.

Following are some basic questions to help in selecting the right GIGAVAC relay or contactor:

1- What is your circuit voltage, or what do you need to isolate?

2- Does the relay need to switch under load, open or close, while current is flowing?

  • If yes and your circuit voltage is under 1500V then GIGAVAC Contactors are probably the best choice
  • If yes and your circuit voltage is over 1500V then GIGAVAC Relays are the best choice
  • If not switching under load then virtually any GIGAVAC product can meet your application needs given other requirements. Some outlined below.
Once voltage and switching requirements are defined there are a number of other factors to look at on the summary and detailed specification pages.

What form is required, SPST, SPDT, or DPDT?

GIGAVAC High Voltage Relays offer all three possibilities. GIGAVAC Contactors are all SPST designs.

Is a Latching, bi-stable, contact form required?

Both GIGAVAC High Voltage Relays and GIGAVAC Contactors offer latching versions.

What coil voltage is required?

GIGAVAC offers standard coil ratings from 5Vdc to 240VAC, product dependent. Some special coil requirements can be accommodated.

Is the application circuit DC, AC, or RF?

GIGAVAC High Voltage Relays and GIGAVAC Contactors can be used in DC or AC circuits. Most GIGAVAC High Voltage Relays are suited for RF applications.

Are there any mechanical size or mounting requirements, PCB mount, panel mount, etc?

GIGAVAC offers a wide variety of package and mounting features. Special packaging requirements may be accommodated with a minimum order volume.

Are there any environmental considerations like temperature extremes, shock, vibration, etc?

The environmental specifications of each product can be found on the corresponding datasheet.

These are just a few of the most common application variables. We welcome a phone call or email to discuss your application requirements to help you select the GIGAVAC product to best meet your needs.