How do Appleton EFD/EFDB factory sealed control stations prevent explosions?

Appleton EFD/EFDB and EDS factory sealed control stations confine arcing of the device within the enclosure, preventing ignition of ignitable atmospheres during motor control operation. The factory sealed design eliminates the need to add sealing fittings and compound at each conduit entrance, reducing installation time and leak points. Heavy duty push buttons are rated 10 Amp, 600 Vac, and contacts are silver cadmium oxide sealed in a lower phenolic chamber isolated from corrosive elements. Stainless steel push button shafts operate within stainless steel bushings for maintenance free operation. A stainless steel helper spring prevents accidental operation in severe vibration installations. Push button models with dust caps are available for areas with excessive dust, moisture, or corrosive conditions.

Selector switches use nylon cam operated heavy duty push buttons for 2 position or 3 position maintained contact. Pilot lights are factory sealed with a red jewel/guard assembly and a 120 Vac/Vdc, 50/60 Hz, 6 Watt Type 6S6 lamp. Combination units allow dozens of push button, pilot light, and selector switch configurations.

What NEC and NEMA ratings do Appleton EFD/EFDB and EDS control stations carry?

The EFD/EFDB and EDS series carry NEC Class I, Division 1 and 2, Groups B (select items), C, D; Class II, Division 1 and 2, Groups E, F, G; Class III; and NEMA 3, 7CD, 9EFG. The diamond footnote indicates select items suitable for Class I Groups B, C, D; Class II Groups E, F, G; and Class III. For Class I Division 1 Group B installations, external seals must be installed at each conduit entrance. For tandem bodies, external seals must be installed within 1.5 meters (5 feet) of each conduit entrance for Class I Groups C and D.

UL certifications include UL 508, UL 698, and UL 1203. cULus Listed file numbers are E10449 and E81751. The hazardous location ratings are specific to each item and series; aluminum body versions added with suffix A may not be suitable for Class I Group B. Cover assemblies installed on a single gang box are suitable for Group B environments but will not be marked Group B.

Which Appleton control station models are suitable for Class I Group B hazardous locations?

Only items marked with the diamond symbol and shaded area in the catalog tables are suitable for Class I Division 1 and 2 Groups B, C, D. For example, in the EFD/EFDB push button table, shaded items include the 1 gang and 2 gang momentary contact units. The 3 device aluminum body is not available, so Group B suitability for those bodies requires the malleable iron version. For Class I Division 1 Group B, external seals are mandatory at each conduit entrance regardless of model.

The EDS rocker arm push button cover assembly, when installed on a 1/2 inch or 3/4 inch single gang box, is suitable for Group B environments but will not be marked Group B. The EDS aluminum body option with suffix A is not suitable for Class I Group B. Pilot light and push button accessories marked with the diamond are suitable for Class I Group B when installed in an enclosure rated for that group.

How do you order Appleton factory sealed control stations with custom hub arrangements?

For blank EFD bodies with brazed threaded hubs, use the EFD Cast Device Box Ordering Information. Select the base EFD device box catalog number such as EFD3NL for a 3 gang blank body, choose a standard hub arrangement diagram, and then assign hub size symbols from the symbol table. Blank symbol 0 means no hub. Brazed threaded hub symbols are 1 for 1/2 inch, 2 for 3/4 inch, 3 for 1 inch. Brazed union hubs use 1E, 2E, 3E. The complete catalog number uses dashes between sections, for example EFD-3NL-8-23203E indicates a 3 gang blank body with hub arrangement diagram 8 and specified hub sizes.

Blank EFD bodies for brazed hubs are non UL listed. If no standard arrangement fits, submit a sketch locating hubs from centerlines of walls and from outside back of box. All hubs will be located in centerlines of walls and evenly spaced unless otherwise specified.

What are the key construction materials and finishes for Appleton control stations?

EFDB control stations use a malleable iron body with a copperfree aluminum cover containing no more than 4/10 of 1 percent copper. SPBB push buttons use a copperfree aluminum upper barrel and phenolic lower barrel with nylon plastic button, except dust cap models which use neoprene buttons. SPLN/SPLS pilot lights use a copperfree aluminum guard and body assembly, steel clamping ring, and tempered glass jewel. SSBA selector switches use a copperfree aluminum operator mechanism, nylon cam, and sealed phenolic contact block. EDS control stations use malleable iron body and cover, copperfree aluminum sealing chamber, and nylon operating handle.

Standard finishes for EFD/EFDB control stations are triple coat: zinc electroplate, chromate, and epoxy powder coat. Push button, pilot light, and selector switch components have a natural finish. EDS control stations have body and cover triple coated; the sealing chamber has a natural finish.

When should you specify aluminum bodies instead of malleable iron for Appleton control stations?

Aluminum bodies are available for many 1 gang and 2 gang EFD/EFDB control stations by adding suffix A to the catalog number. For example EFDB150-U1 becomes EFDB150A-U1. However aluminum bodies are not suitable for Class I Group B locations. For 3 device bodies and tandem bodies, aluminum body is not available. In corrosive environments where weight savings is not critical, malleable iron with triple coat finish offers durability.

What accessories and modifications are available for Appleton push buttons and pilot lights?

Push button lockout guards are standard on all EFD/EFDB momentary push buttons, with holes accepting locks up to 1/4 inch hasp. A securing rod for lockout guard is available as NBL SR or suffix SR. Selector switch lockout devices SBL 3 Q permit locking in any position. Colored mushroom heads are available in red NMRBRE, green NMRBGR, and black NMRBBL. Pilot light jewels and guards come in amber JGBA, blue JGBB, clear JGBC, green JGBG, and opal JGB0. LED replacements include red LEDR, green LEDG, and amber LEDA. Transformers for pilot lights include TR2 for 220/120 Vac, TR3 for 277/120 Vac, TR4 for 440/120 Vac, and TR5 for 550/120 Vac. Nameplate mounting brackets NPBRKT EFDB and NPBRKT C0NT simplify circuit identification. Custom nameplates are not available.

Summary

Appleton EFD/EFDB and EDS factory sealed control stations are rated Class I Division 1 and 2 Groups B (select items), C, D; Class II Groups E, F, G; Class III; NEMA 3, 7CD, 9EFG.
Heavy duty push buttons and selector switches are rated 10 Amp, 600 Vac, with silver cadmium oxide contacts sealed in a phenolic chamber.
For Class I Division 1 Group B installations, external seals are required at each conduit entrance; tandem bodies require seals within 1.5 meters for Groups C and D.
Aluminum bodies with suffix A are not suitable for Class I Group B; aluminum body is not available for 3 device or tandem bodies.
Pilot lights ship with a 6 Watt 120 Vac Type 6S6 lamp and red jewel; LED and colored jewel options require suffix changes.

Step-by-step

For Class I Division 1 Group B installations, install external seals at each conduit entrance before energizing the control station.
For tandem bodies, install external seals within 1.5 meters (5 feet) of each conduit entrance for Class I Groups C and D.
When mounting the NPBRKT nameplate bracket, position it between cover screws and cover, never between the ground joint flame path and backbox.
Torque cover screws to 35 inch pounds when securing the nameplate mounting bracket.
Add suffix A to the catalog number only when aluminum body is acceptable and the location is not Class I Group B.

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Appleton EFD, EFDB and EDS Factory Sealed Control Stations: Class I Group B Selection Guide