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CircuitSpy FAQs

This page provides some frequently asked questions and answers on CircuitSpy Wireless Voltmeter.

CircuitSpy - Wireless Voltmeter / Voltage Measuring Terminal - Portable Kit    
Why do I need CircuitSpy?

Fault finding on and commissioning of electrical and control system equipment can be inconclusive if performed on a de-energised circuit.  However, working on energised circuits ( working live, live electrical work and live testing ) exposes the worker to the risk of an electric shock and an arc flash explosion.  This elevated safety risk has led many companies and authorities to discourage energised work by introducing onerous procedures and requiring the use of cumbersome personal protective equipment ( PPE ). 

CircuitSpy allows electricians to perform voltage measurements on energised equipment within a closed electrical panel.  In essence, it means that you can do your job safely while at the same time, reducing frustration and costs.


What is so special about CircuitSpy?

CircuitySpy Wireless Voltmeter / Voltage Measuring Terminal was designed to:

  • Provide safe, testing facilities for electricians.  Put simply, to prevent the need to work live, conduct live electrical work and perform live commissioning.

  • Provide circuit status where circuits are located in difficult or inconvenient to access areas. 

  • Be used as a temporarily installed, test tool for multicahannel, fault finding and commissioning purposes.

  • Be installed permanently in place of feed through terminals in locations where control system IO would not be warranted for operational or cost reasons.


Why is CircuitSpy different to the competition?

CircuitSpy is different to the competition because:

  • CircuitSpy is a multichannel device.  This means that coinciding events on adjacent circuit nodes are detectable eg three phase measurements.  In addition, there is no place probe, energise, measure, deenergise, move probe, energise, measure, deenergise, move probe etc... 

  • CircuitSpy reports to a webpage, not to an App.  This means that a device with a web browser is all that is necessary to view CircuitSpy.

  • CircuitSpy uses WiFi, not Bluetooth.  This translates to a more robust radio path.

  • CircuitSpy Portable Comms Module incorporates fused test leads, DIN rail terminal test pins and magnetic electrode connections. 

  • CircuitSpy Fixed Comms Module incorporates feed through terminals and is DIN rail mounted, so it can be used as a direct replacement for DIN rail feed through terminals.


How can I be sure that CircuitSpy will work in my electrical panels?

The simple answer is that you can be fairly confident based on the extent of testing that we have done for you.  In fact we have tested a reliable external WiFi signal when CircuitSpy was installed in the following panels: 

  • Mild Steel, Motor Control Centre ( MCC ) - cable ways and drive cells / buckets

  • Marine Grade Stainless Steel ( 316SS ) control panel

  • Aluminium control panel

  • Fibre Reinforced Plastic ( FRP ) control panel

Every panel installation is different so radio certainty is difficult, perhaps foolish, to guarantee.  However we are yet to find a panel where it does not work!


How does CircuitSpy compare with Fluke Connect CNX?

A comparison between Fluke Connect CNX and CircuitSpy for typical electrical maintenance functions ie voltage measurements is detailed inthe table below:


Fluke Connect CNX CircuitSpy
Voltage Channels 3* 8
Voltage Types AC Only or DC Only AC and DC
3 Phase 480VAC, 415VAC Measurements Yes* Yes
Fixed Installation Capable No Yes
Test Pins (DIN Rail Terminals) 0 4
Alligator Clips 6* 4
Magnet Electrodes (Tunnel Terminals) 0 4
Web Browser Viewing No** Yes
Batteries Required 9 x 1.5V, AA 1 x 9V
Size 0.0011m3 0.0004m3
Weight 1.0kg < 0.15kg
Price Approx 800 USD Approx 885 USD

* When 3 x CNX Voltage Modules are used

** Need special software installed


We have a comprehensive DCS / PLC system that we can use for fault finding so why would we need CircuitSpy?

If your site has a comprehensive DCS / PLC you might have a rough idea of where a problem might be.  Using your DCS / PLC for troubleshooting you will get a digital “on” or “off” status at most circuit nodes.  Where CircuitSpy offers you more is where:

  • Because of the high costs of IO, not all nodes are usually monitored by IO eg MCC drive wiring, emergency stop strings, self-contained packaged plant, remote pumps, mobile equipment etc. and the fault cannot be reliably pin pointed without live testing

  • Analog voltage measurements are required sometimes as digital states are not always sufficient eg power supply voltages, voltage drop measurements required to highlight correct cable sizes (commissioning QA), voltage drops on starts to highlight nuisance trips (fault finding)

  • Panel internal temperature monitoring highlight nuisance trips (fault finding) would be helpful

In summary, if you have a voltmeter on your site now it probably means that there are occasions when your DCS / PLC can't service 100% of your fault finding needs.  These occasions are when you need CircuitSpy.