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IRISS VPFR Windows Installed on Switchgear Cabinets
- Published: Thursday, 25 September 2014 18:45
Based in London, the company provides an excellent example of how the inclusion of thermal imaging windows reduces inspection costs and makes maintenance smarter, without increasing health and safety risks.
‘Caution, keep this door closed’ is a sign most maintenance engineers will encounter on electrical switchgear cabinets. This warning alerts them to the serious prospect of arc flash that has the potential to cause serious and even fatal burns. As a result there are two options.
The first option is to shut down the electrical system so that a team of electricians can remove the panel and inspect the components. The drawback is that this solution only allows faulty components, such as terminals, to be identified. As the system isn’t under load there is no possibility of assessing, for example, the heat rise in a bus bar.
The second option is to leave the system under load; have the team of electricians suit up in full PPE and then remove the panel and inspect the components. While this option obviously allows the electricians to better assess what may be wrong, it also exposes them to extremely hazardous conditions that could cause an arc flash explosion resulting in severe or even fatal injuries.
It was for this type of regime that CTS had been engaged by a client in central London. Electrical inspection was undertaken during annual shut down and although the systems continued to work well as a result of its diligence, CTS recognised the potential pitfalls.
Safe, live inspection
An increasingly preferable solution for many companies is predictive maintenance using thermal imaging and IRISS polymer infrared (IR) windows. These provide data collection points that keep the thermographer safe whilst allowing him or her to inspect the fully energised system, obtaining both quantitative and qualitative information. And this is precisely the plan that CTS proposed to its client.
The choice of IRISS’s polymer IR windows was based on suitability for the job and cost. Crystal windows were considered but dismissed for several reasons. Firstly they carry a significant risk of breakage, even an electrician slamming an enclosure can cause a crystal window to shatter. In contrast an IRISS window has an unconditional lifetime warranty against breakage. It is reinforced by an aluminium honeycomb grill and is resistant to moisture, humidity, vibration and high frequency noise.
Cost was another factor
Not only do IRISS windows outlive crystal alternatives they are also cheaper too. Additionally IRISS also offers custom solutions, where they configure their polymer IR windows to any shape or size, a capability that is not achievable with crystal technology. This means a window can be supplied, for example, that allows the inspection of a busbar or multiple components in a single pass of the camera.
The business case that CTS presented to its client, for installing twelve IRISS VPFR windows on switchgear cabinets, was compelling. The client would achieve the best of both worlds; substantially reduced risk of system failure and lower maintenance costs. As a result 12 windows were installed, a process that was completed by IRISS over a weekend.
“By installing IRISS windows we can now carry out inspection whilst the systems are live but in a safe and guarded condition,” explained CTS Director, Kim Harris. “As the process is not intrusive it presents minimal risk to business operations and the health and safety of employees.”
He continued: “And as we can now inspect these electrical systems during normal working hours, instead of during an electrical maintenance shut down, the cost to the client has also been reduced. The payback, in monetary sense, has been almost immediate. Also the new regime will allow us to inspect systems that were considered too risky as their incident energy calculations exceeded PPE ratings.”
Thermal imaging windows are just one piece in the jigsaw for safe and efficient electrical inspection however. IRISS is leading the field in expanding the scope of this technology by offering a range of complementary electrical maintenance safety devices (EMSD).
These EMSD provide highly valuable information on the health of the live system and include ultrasound ports for airborne ultrasound, external voltage detection ports and voltage tap off connections for motor current analysis.
The technology also allows the use of online monitoring systems to transmit data to the client via wired or wireless sensor technology. The latest addition to the IRISS range, Delta T Alert™, bridges the gap between electrical inspections by regularly recording and reporting critical temperatures within electro/mechanical enclosures.