Intrinsically Safe Portable Radios

Overview

What is Intrinsically Safe?

Intrinsically Safe is electrical equipment that is incapable of releasing sufficient electrical or thermal energy under normal or abnormal operating conditions to cause ignition of a specific hazardous mixture and air. This rating is required for equipment to be used in Division 1 environments.

What is Non-Incendive?

Electrical equipment that is incapable of releasing sufficient electrical or thermal energy under normal operating conditions only which cause ignition of a specific hazardous mixture and air. This rating is required for equipment to be used in Division 2 environments.

Intrinsically Safe and Non-Incendive approvals are classified by classes, divisions, groups and a temperature rating. These can be defined as follows:

Class: this can be defined as relating to the industry type in which the equipment will operate. Classes range from Class I to Class III, where Class I is for such industries as petroleum/gas/oil etc, Class II is for such industries as heavy engineering (ironore, magnesium, coke, coal ,charcoal, etc.) and the food industry (starch, grain processing, eg. flour mills etc. Class III is for industries dealing with fibers.

Division: this can be defined as relating directly to the proximity of the risk. That is, if the hazardous mixture is in direct contact with the environment (Division 1, closer proximity) or is it enclosed within a container or system, or ventilated (Division 2, further proximity).

Group: this is the type of atmosphere and ranges from Group A through to Group G. Group A covers atmospheres containing Acetylene gas and Group B covers atmospheres containing Hydrogen gas. These are both very unstable and explode at low temperatures. Group C covers vapours of Ethylene and Group D covers Propane vapour atmospheres. Group E includes atmospheres containing various types of metal dust, Group F has coal dust and Group G contains grain dusts.

Temperature Rating:
Temperature rating alone is probably the most important factor for IS handportables. The temperature rating is a maximum temperature (°C) and an associated identification code. The temperature rating means that where any hazardous mixture explodes/combusts at less than the stated maximum temperature, then the handportable cannot be used in this environment. If units do not meet the temperature requirement then there is no basis for supplying radios regardless of whether or not the units meet the other standards i.e. class, division and group.

It is important to note that Tait does not wish to advise the customer what ratings they would need for their work environment, as liability becomes an issue here. There are a number of publications which detail combustion thresholds of hazardous
mixtures and the customer should research this themselves.

What Tait Can Offer

Tait Electronics currently have both the following Factory Mutual Approvals for the Orca 5000 Series IS product range (all bands and variants):

Approved as Intrinsically Safe for use in Class I, Division 1, Groups C, D, E, F and G with a temperature rating of T3C (160ºC).

Approved as Non-Incendive for use in Class I, Division 2, Groups A, B, C and D with a temperature rating of T3C (160ºC).

The FCC RF bands:
Are only Approved as Non-Incendive for use in Class I, Division 2, Groups A, B, C and D with a temperature rating of T3C (160ºC).

What this means:
Class I, Division 1: This is a location in which:
(a) hazardous concentrations of flammable gases or vapours exist continuously, intermittently, periodically under normal operating conditions;
     OR,
(b) hazardous concentrations of such gases or vapours may exist frequently because of repair or maintenance operations or because of leakage;
     OR,
(c) breakdown or faulty operation of equipment or processes that might release hazardous concentrations of flammable gasses or vapours and might also
     cause simultaneous failure of electric equipment.

Class I, Division 2: This is a location:
(a) in which volatile flammable gasses are handled, processed or used, but in which the hazardous liquids, vapours or gases will normally be confined within 
     closed containers or closed systems from which they can escape only in the case of accidental rupture or breakdown of such containers or systems, or in
     the case of abnormal operation of equipment;
     OR,
(b) in which hazardous concentration of gases or vapours are normally prevented by positive mechanical ventilation and which might become hazardous 
     through failure or abnormal operation of the ventilating equipment;
     OR,
(c) that is adjacent to a Class I, Division 1 location and to which hazardous concentrations of such gases or vapours might occasionally be communicated
     unless such communication is prevented by adequate positive-pressure ventilation from a source of clear air and effective safe-guards against ventilation
     failure are provided.

Groups A, B, C and D:
These are various atmospheres for which the Tait handportables are approved to operate in, in conjunction with the above information and are rated as follows:
Group A atmospheres containing acetylene gas
Group B atmospheres containing hydrogen gas
Group C atmospheres containing ethylene vapours
Group D atmospheres containing propane vapours
Temperature T3C (160ºC)
Where any hazardous mixture explodes at less than 160ºC, Tait handheld portables are not approved to operate in these environments. This is a very high temperature rating in the sense that many hazardous mixtures explode/combust at less that 160ºC.

Intrinsically Safe Accessories

The Tait Orca 5000 IS range of portables are only approved to be Intrinsically Safe when used in conjunction with the IS approved accessories and FM Approved battery packs.

IS Batteries

TOPB200-IF TOP5000 Battery 1500mAh FM-IS NiCd
TOPB500-IF TOP5000 Battery 2000mAh FM-IS NiMH
Note: If a customer has a requirement to charge their batteries within a hazardous environment, we cannot supply our chargers as these are NOT FM™ Approved.

IS Audio Accessories

The following audio accessories are FM™ Approved as Intrinsically Safe when used with FM™ Approved Tait Orca 5000 IS radios:
TOPA-AA-003G TOP5000 Speaker Microphone Otto FM-IS
TOPA-AA-103G TOP5000 Speaker Microphone Otto FM-IS D-Clip
TOPA-AA-004G TOP5000 Speaker Microphone Otto FM-IS RF
TOPA-AA-104G TOP5000 Speaker Microphone Otto FM-IS RF D-Clip
TOPA-AA-005G TOP5000 7.5mm (0.29in) Accessory Adaptor - FM-IS
TOPA-AA-012 TOP5000 Over-the-head Headset 7.5mm (0.29in) - With Boom Mic
TOPA-AA-013 TOP5000 Behind-the-head Headset 7.5mm (0.29in) - With Boom Mic
TOPA-AA-008 TOP5000 Speaker Microphone Otto 7.5mm (0.29in) FM-IS
TOPA-AA-001G TOP5000 Speaker Microphone Foster FM-IS
TOPA-AA-101G TOP5000 Speaker Microphone Foster FM-IS
TOPA-AA-015G TOP5000 Speaker Microphone Otto Profile FM-IS
TOPA-AA-115G TOP5000 Speaker Microphone Otto Profile FM-IS D-Clip
Note: that any other accessory that can plug into an approved audio accessory is also approved.

IS Antennas

TOPA-AN-101 Helical VHF Antenna (Short)
TOPA-AN-102 Helical UHF Antenna (Short)
TOPA-AN-201 Helical VHF Antenna
TOPA-AN-212 Whip UHF Antenna
TOPA-AN-204 Whip 800MHz Antenna
TOPA-AN-205 Whip 900MHz Antenna
TOPA-AN-301 Helical 66MHz Antenna

IS Servicing

The radios must be serviced at Tait Electronics and cannot be serviced under any circumstances at branch level. A requirement of the IS approval process from the approval body (namely Factory Mutual Corporation) require that the radios are serviced at an audited plant. Presently, the following facilities have this approval: Tait Radio Communications, 535 Wairakei Road, Burnside, Christchurch, New Zealand, Manufacturing plant.