trical workers maintain, inspect or repair. The labels shall indi-cate the level of Arc Flash hazard (see example) and the rec-ommended PPE when working on the equipment. Thoseinvolved in electrical testing and the employment of electricalworkers must implement safety programs and procedures thatfollow NFPA 70E. If there is non-compliance and an accidentoccurs there is legal liability that can result in citations, workshutdown, fines or other sanctions. It is generally recommendedthat electrical testing and maintenance workers use tools with thelatest highest safety rating (CAT IV) to be compatible with theirsafety practices. Without this rating, the worker could be injuredif a sudden transient overvoltage occurs and the tool creates anarcing flash-over. The four CAT environments and their maxi-mum transient overvoltages that testing tools must withstandare depicted below (as per IEC/EN 61010-1 for phase to ground)

Most older test meters are designed to sustain transient over-voltages in CAT III.Higher-rated CAT IV tools have improved protection cir-

cuitry. CAT IV 600V instruments are a better choice and aresuitable for all CAT test environments at 600V or below.• CAT (Category) IV refers to power lines at the utility connec-tion, the origin of installation or service entrance. It includesoutdoor overhead and underground cable runs that could beaffected by light-ning, utility meterlocations and pri-mary breakers orfuses.• CAT III deals with

6 Electrical Products & Solutions • May 2009

IntroductionThe choice of a test meter, power monitor or datalogger for a

power study must now take into account the safety standardscurrently in force to protect electrical workers under NationalFire and Protection Association (NFPA) 70E standards. Whenselecting electrical testing tools users are confronted with thefollowing considerations:1. Does the meter meet existing safety standards?2. Does the meter meet both my company or organization’ssafety and measurement goals?

3. Does the meter improve worker safety?

We assert that a CAT IV safety rating and Bluetooth wire-less communication are attractive and practical features that arecompatible with NFPA 70E safety programs and procedures. Inthis article we discuss how these design features of the latestpower testing meters enhance worker safety and provide anoverall better “user experience”.

The Impact of NFPA 70E onElectrical Testing and Meter DesignSafety in the electrical testing industry has taken on a new

level of importance with the focus on Arc Flash hazards that isembodied in the NFPA 70E Standard for Electrical WorkplaceSafety. NFPA 70E covers the range of electrical safety issuessuch as work practices for maintenance, installation and repair

activities. It is intended to befollowed by employers, em-ployees, engineers, electricians,their supervisors, and new hiressuch as apprentices. OSHA(Occupational Safety & HealthAdministration) bases its elec-trical safety mandates on theNFPA 70E standard. It providesguidance on employee training,how to implement an effectiveelectrical safety program, work

planning and procedures such as lockout/tagout rules. It specif-ically prescribes the use of PPE (Personal Protective Equipment)such as gloves, visors and fire-retardant clothing. Meters andtest equipment are also classified as PPE.To comply with NFPA 70E owners of electrical equipment

and systems must display warning labels on equipment that elec-

ELECTRICAL TESTINGAND NFPA 70E:Meters with Bluetooth and

Cat IV Rating are SafestBy Michael Daish

Feature • SUMMIT TECHNOLOGY

Overvoltage Protection Categories

CAT II 600V

CAT III 300V

CAT III 600V

CAT IV 300V

CAT III 1000V

CAT IV 600V

CAT IV 1000V

Overvoltage Withstand Capability

4000V

6000V

8000V

12000V

distribution level wiring, 480-volt and 600-volt circuits such as3-phase bus and feeder circuits, motor control centers, loadcenters and distribution panels. Also included in CAT III areswitchgear, motors, transformers and similar fixed loads, andloads that can generate their own transients.

• CAT II covers outlet receptacles and their plug-in loads such asappliances and portable tools.

• CAT I refers to electronic equipment and circuits.

Personal Protective Equipment and MeterOperation and DesignConsider that under NFPA 70E it is now mandatory to wear

personal protective equipment (PPE) when installing test equip-ment. The following table shows some examples:

Meter design and operation must now take the NFPA safetyrequirements into consideration and make meter operation eas-ier while wearing PPE. In the following pictures we see aworker wearing a PPE level 1 Nomex® fire-retardant overall,gloves, and a visor. The next picture shows a level PPE 4 suit;sometimes referred to as a “Homer Simpson” suit. It is claus-trophobic and uncomfortable to wear even for a few minutes. Itsubstantially restricts movement, and the handling and opera-tion of tools, meters and instruments. One can see that it would

be difficult to program any meter while wearing such cumber-some PPE. With either level of PPE the hood or visor impairsclear vision of a meter display and keypad legends. The “thick-fingered” leather gloves eliminate the tactile feel necessary forlocating and operation of buttons on a keypad. There is a saferand better way.Bluetooth communications elegantly solves the problem of

safely operating a meter since Bluetooth wireless communica-tions allows you to operate the meter remotely from a PC orPDA, well away from high voltages. A power study involvesconnecting probes to the power conductors to sense voltage andcurrent, and these connections must be made while wearing themandatory PPE. After installing the probes the user can retreatseveral feet to a safe zone, take off the visor and gloves and

comfortably viewwaveforms, phasorsand power metersfrom a PC or PDA tocheck connections andinitiate a monitoringsession remotely using Bluetooth.Remote operation of a testing me-

ter is ultimately the safest practice.The new PowerSight meters are idealfor NFPA 70E safety programs. ThePowerSight model PS2500 PowerLogger, PS3500 Energy Analyzerand PS4500 Power Quality Analyzerall combine the safety benefits ofBluetooth communications and CATIV rating while also meeting the mea-surement requirements for energystudies, harmonics and power qualityinvestigations. They also have re-movable SD memory card slots for storing measurement data,logs and disturbance events. This data can be transferred to a PCeither wirelessly by Bluetooth or by the memory card.

Safely Leaving the Meter Behind to MonitorMost power studies are performed indoors and require leaving

the meter unattended for days or weeks. The user is confrontedwith the problem of how to install the monitor safely and unob-trusively. We do not want the meter to

8 Electrical Products & Solutions • May 2009

Feature • SUMMIT TECHNOLOGY (Continued from page 6)

Protective Clothing and Personal Protective Equipment (PPE) As Defined in NFPA 70E-2004

Flash Hazard Category 0Cotton underwearLong sleeve cotton shirt &pantsSafety glasses or goggles

Flash Hazard Category 2Cotton underwear and T-shirt(short-sleeve)FR shirt & pants (or FR coverall)Hard hatSafety glasses or gogglesArc–rated face shieldHearing protectionLeather gloves and shoesVoltage rated gloves and tools

Flash Hazard Category 4Cotton underwear and T-shirt(short-sleeve)FR shirt & pants (or FR coverall)Hard hatSafety glasses or gogglesHearing protectionLeather gloves and shoesVoltage rated gloves and toolsMultilayer flash suit and flashsuit hood (> 40 cal/cm2)

(Continued on page 12)

be tampered with for safety rea-sons or risk losing or corruptingcaptured data. The compact size(3.89” x 7.72” x 1.58”) and lowweight (1.1 lbs) of the Power-Sight meter means that it can beeasily installed in voids and hid-den away in electricalswitchgear, panels and similar

locations where electrical stud-ies are performed. The pictureshowing a PowerSight metermonitoring a panel highlightshow the meter’s compact sizeand low weight has advantages.In this situation the meter is sus-pended high-up in a soft case bya strap around conduit. The me-

12 Electrical Products & Solutions • May 2009

Feature • SUMMIT TECHNOLOGY (Continued from page 8)

ter is well out-of-the-way; it is a safe in-stallation and is far less susceptible to beingtampered with.

ConclusionSafety standards and procedures must be

adhered to when using meters for energyaudits, power quality studies, or simple datalogging. The latest revision of NFPA 70Especifies the appropriate PPE (such asclothes, face-shields, and gloves) accordingto the flash hazard severity at specified volt-age and energy levels. Personal protectiveequipment (PPE) involves wearing cum-bersome suits, thick gloves, hoods or visorswhich interfere with the worker’s freedomof movement, vision and dexterous controlof tools. The design and operation of elec-trical testing tools such as meters, powermonitors and dataloggers must take boththe safety regulations and the worker’s op-erational circumstances into consideration.With respect to the design of a meter, it

must withstand transient overvoltages inorder to protect the user. The CAT rat-ings described above specify the level ofwithstand voltage for different nominalsupply voltages. A CAT IV 600V/8000Vrated tool means that it is suitable for usein all locations on conductors that have upto 600V phase to ground and can with-stand an 8000 volt transient overvoltageevent. The PowerSight models PS2500,PS3500 and PS4500 are CAT IV600V/8000V rated.Bluetooth wireless communication is an

excellent solution that provides the bestsafety experience. Bluetooth remote oper-ation allows the user to remove the visorand gloves and safely operate the meter at adistance up to 20 feet away using a PC orPDA. This approach actually provides abetter user experience since the user cantake advantage of the size and higher reso-lution of a PC display. With the PowerSightManager software the user can view wave-forms more clearly, take waveform snap-shots and save data on the PC. After data isdownloaded the user can expand graphs fordetail, export the data to Excel and generateprofessional-looking final reports as Wordor pdf documents. �

About the author

Michael Daish is the Vice PresidentSales & Marketing for Summit Technol-ogy, Inc., www.PowerSight.com