30NO-120A

MDI mercury relays are all designed to meet the highest demands of our industry and are proudly manufactured in Michigan!

Our mercury relays, also called mercury contactors, are hermetically sealed with high quality glass to metal seals. The stainless steel tube is totally encapsulated in high grade, UL approved epoxy to prevent moisture damage and voltage breakdown.

Additional coil voltages and options are available, if you do not see what you need on the website please contact customer service.

An "H' at the end of the part number means that the mercury relay is back-filled with Hydrogen and are for inductive (motors) or lighting loads. The relays without an 'H' in the part number are filled with Argon and are meant to be used for resistive loads (i.e. heaters).

The -18 in the part number means there is a metal strap around the poles. If there is not a -18 there are nylon straps around the poles. Single pole relays do not have either as there is only one pole. All 100 amp relays have a metal strap even though they do not have a -18! Hope this helps, call us if you need us.

Mercury relays are also referred to as mercury contactors, mercury relay switches, mercury contactor relays and mercury displacement relays.

Marshall Wolf Automation is your authorized MDI distributor! Have a Durakool art number? We can easily cross reference it, just contact us.

Need More Information?

• MDI Mercury Relay Universal Catalog
• MDI Cross Reference - Durakool, Watlow and More!
• Article on California Ban for Mercury Relays & Switches