Relays: ATEX Directives & HAZLOC Compliance

Overview

The Challenge

Government regulations around the world restrict the use of refrigerant gases that deplete the ozone layer and have a global warming potential. These low flammable gases are often replaced by gases such as R290 (propane), which is a highly flammable refrigerant. With more flammable gases, ignition sources are a safety challenge.

Relays are regarded as ignition sources, driving the need for explosion-proof relays.

Relays as an Ignition Source

Arcing can occur between the contacts when the relay is in operation and ignite in combination with a refrigerant such as R290 (propane) and the air. This can cause an explosion.

The use of relays depends on the degree of risk and condition of explosion material. The relay must not be located at a high-risk zone or location.

ATEX and HazLoc Compliance

Atex is the EU directive for “Equipment and Protective Systems Intended for Use in Potentially Explosive Atmospheres,” and is the set of requirements for relays in these zones. In the US and Canada, these risk areas are called hazardous locations (HAZLOC) and fall under UL/CSA definitions. Devices qualified to be used in these areas are called HAZLOC-rated devices.

ATEX uses a zone classification for relays. The use of relays depends on the degree of risk and condition of explosion material. The relay must not be located at a high-risk zone.

• zone 0 (high risk area)
• zone 1, (less high-risk area, explosion risk possible location), vapor and liquid
• zone 2 (low risk area, no explosion possible location). This is the zone where relays can be use but must comply with ATEX

For use in the EU, relays need to comply with the ATEX Directive covering equipment and protective systems intended for use in potentially explosive atmospheres in accordance with IEC 60079 testing method:

• IEC 60079-1 (Ex) II 3 G Ex dc IIA Gc (flux free cover)
• IEC 60079-15 (Ex) II 3 G Ex nC IIC Gc (plastic sealed cover)

UL/CSA HAZLOC uses a somewhat similar class, division and zone classification structure to define the properties of location risk.

In the US and Canada, relays must comply with the UL/CSA applicable explosion-proof standards, which may include:

• UL 121201 (Class I, Division 2)
• UL 121201 (Class I, Division 2, Group A, B, C and D
• CSA C22.2 213-17 (Class I, Division 2, Group A, B, C and D).

Purpose of Regulations

• Prevention of static charge
• Prevention of sparks from igniting due to friction, impact, and wear
• Prevention of ignition due to temperature rise due to same as above
• Certification is performed by categorizing the equipment used for each hazardous area (zone or class/division/group)

If the relay is compliant or integrated in a metal housing preventing flammable gasses to enter, relays no longer considered an ignition source.

Link to ATEX Directives

Link to UL Standards

Explosion Proof Certificate

The relay supplier must verify that the relay does not explode in accordance with the applicable testing method.

Testing is done by the UL safety house by opening/closing contacts in a flammable gas environment.

FCL Components Relays

FCL Components FTR-K1, FTR-F3 and FTR-MY series relays are certified compliant with UL/CSA HAZLOC and ATEX for certain low-risk areas with minimal explosion likelihood.

FCL Components Approved ATEX Relays

Relay series	FTR-MY	FTR-F3	FTR-K1
Contact Rating (A)	5A	5A	16A
Contact Rating (A)	5A	5A	16A
Protection Structure	Plastic sealed	Plastic sealed	Plastic sealed	Flux free
Contact Form	1 form A	1 form A	1 form A, 1 form C
Dimensions (W x L x H)	5 x 20 x 12 (slim)	7 x 20 x 15 (small)	12.7 x 29 x 15.7 (low profile)
ATEX Compliance	IEC/EN 60079-0 IEC/EN 60079-15 (type "nC")	IEC/EN 60079-0 IEC/EN 60079-15 (type "nC")	IEC/EN 60079-0 IEC/EN 60079-15 (type "nC")	IEC/EN 60079-0 IEC/EN 60079-1 (type "dc")
UL/CSA HAZLOC Compliance	UL121201 (Class I, Division 2)	UL121201 (Class I, Division 2)	UL 121201 (Class I, Division 2, Group A, B, C and D) CSA C22.2 213-17 (Class I, Division 2, Group A, B, C and D)	-
Datasheets	FTR-MY	FTR-F3 TV FTR-F3	FTR-K1-85degC FTR-K1-105degC Flux free FTR-K1-105degC Plastic sealed

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