Impact Testing of Power LOC Enclosure Part# PL-CII ... - iLECSYS

Impact Testing of Power LOC Enclosure
Part# PL-CII/3SW-ESP
PA05/04990
Customer Network Rail Order No: PA05/04990 iLECSYS internal
Job description Class 2 Power LOC, Glass Filled Polycarbonate
Ref: ILS100005
Introduction
The iLECSYS FSP series of assemblies are based on high quality polycarbonate enclosures. The
enclosures are designed & type tested to withstand very severe environmental conditions while
maintaining an excellent dielectric strength. This makes the units entirely suitable for an outdoor
Class II installation.
The enclosures are certified to withstand mechanical impact to IK09 in accordance with BS EN62262
& prior to machining, the enclosures have an ingress protection of IP66/67 in accordance with BS EN
60529.
ClassII suitability.
The nature of the non-conductive enclosure is such that it is an ideal solution for Class II equipment.
The range of enclosures have successfully been tested to 8kV for 60s in accordance with EN
62208:2003 clause 9.9. The enclosure on test did not in fact break down until the test voltage
reached 18kV.
iLECSYS ltd are satisfied that the enclosure is the only realistic option for a Class II solution as, the
enclosure itself is constructed entirely from an insulating material.
As defined in BS7671:2008, section 416.1.
“Paint, varnish, lacquer or similar products are generally not considered to provide adequate
insulation for basic protection in normal service”.
It is our considered opinion that due to the harsh environment that are the nature of trackside
installations, that a paint or lacquer coating which MAY be fine on first installation will degrade, chip
and possibly peel during its lifetime and would seriously compromise the safety and integrity of the
installation. Such a coating would be impractical to maintain and in most cases impossible to detect
any breakdown of the protective coating with only a cursory visual inspection. Any breakdown may
only be apparent with an electrical hi-potential test which would be a difficult & time consuming
task to perform in situe.

Image
Part# PL-CII/3SW-ESP

Impact resistance & durability
In order to substantiate the claims made by the enclosure manufacturer, a series of mechanical tests
were performed on a completed unit. One of the main terminal covers was attacked with various
tools to simulate vandalism or, careless use of tools during maintenance activities. The
polycarbonate was very difficult to damage and a determined effort had to be made in order to
cause noticeable damage to the assembly.
Prior to damage
The PL-CII/3SW-ESP assembly serial#01-000487 prior to damage, with incoming terminal cover
removed to allow connection of test probes. The impact testing was carried out on the RH ‘Outgoing
Terminals’ compartment cover shown.

Case 1 – Light Damage
The cover was deliberately scratched with the metal blade of a 3mm electrician’s
screwdriver (pictured). The effort required to make the scratch was far greater than damage
that might occur from a simple ‘slip of the hand’ or a dropped tool. The scratch produced is
less than 1mm deep and does not penetrate the enclosure.
IP rating unaffected.
Structural integrity of the assembly is maintained.
Maintenance unnecessary.
Class II integrity unaffected.

Testing 1.
The damaged cover was surrounded in aluminium foil & the assembly was subjected to an insulation
resistance test at 1000VDC. The addition of the foil was to make sure the scratch was connected to
the test probe. The test was successful, the insulation reading being measured at >1000M Ohms.

Testing 2.
The damaged cover was surrounded in aluminium foil and a second piece of foil was put on the
inside of the cover. The assembly was subjected to an insulation resistance test at 1000VDC. The
addition of the foil was to make sure the area adjacent to the scratch was connected to the test
probes. The test was successful, the insulation reading being measured at >1000M Ohms.

Case 2 – Deeper & wider gouge.
The cover was scratched further & deliberately gouged with the metal blade of a 3mm
electrician’s screwdriver and the blade of a 100mm chisel. A 6lb club hammer was used in
conjunction with the chisel to deepen & widen the scratch. Multiple scratch damage was
created; the scratches were of varying depths up to and exceeding 1mm in depth but, not
penetrating the enclosure.
IP rating unaffected.
Structural integrity of the assembly is maintained.
Maintenance unnecessary.
Class II integrity unaffected.

Testing 3, Tools Used – Deeper & wider gouge.
The damaged cover was surrounded in aluminium foil and a second piece of foil was put on the
inside of the cover. The assembly was subjected to an insulation resistance test at 1000VDC. The
addition of the foil was to make sure the area adjacent to the scratch was connected to the test
probes. The test was successful, the insulation reading being measured at >1000M Ohms.

Testing 4.
The damaged cover was again surrounded in aluminium foil and a second piece of foil was put on
the inside of the cover. The assembly was subjected to an insulation resistance test at 1000VDC. The
addition of the foil was to make sure the area adjacent to the scratch was connected to the test
probes. The test was again successful, the insulation reading being measured at >1000M Ohms.

Case 3 – Deliberate damage – non penetrating.
The cover was attacked in the same area with the previous tools, plus, a woodsaw and the
edge of a triangular engineers file. The damage continued until a definite scar appeared on
the inside of the cover. The gouge was repeatedly scraped, hammered and struck so that
the damage depth was far in excess of 1mm and on the limit of penetration.
IP rating unaffected.
Structural integrity of the assembly is maintained.
Maintenance unnecessary.
Class II integrity unaffected.

Depth of damage
The depth of the damage varies but, was measured in excess of 1mm.

Inside of enclosure
It can be observed in the above picture that the damage is almost penetrating the cover and
has left a noticeable scar on the polycarbonate.

Testing 5
The damaged cover was surrounded in aluminium foil & the assembly was subjected to an insulation
resistance test at 1000VDC. The addition of the foil was to make sure the deepest scratch was
connected to the test probe. The test was successful, the insulation reading being measured at
>1000M Ohms.

Testing 6
The damaged cover was again surrounded in aluminium foil and a second piece of foil was put on
the inside of the cover. The assembly was subjected to an insulation resistance test at 1000VDC. The
object of the test was to make sure the probes were applied to the scarred area of polycarbonate.
The test was successful, the insulation reading being measured at >1000M Ohms.

Case 4 – Deliberate penetration.
The images demonstrate the level of force required to penetrate the enclosure. It took more than
twenty five blows on the already damaged area to fully penetrate the cover.

Tools used
The images above show that a definite split has been created in the polycarbonate cover.

Conclusions
Despite the crack in the cover, the unit still passed both electrical tests. In reality, iLECSYS would
recommend replacement of the cover. This level of damage would not compromise the Class II
properties of the assembly but, would affect the IP rating and allow water to ingress in extreme
circumstances such as flooding or direct driving rain.
It is extremely difficult to damage the polycarbonate enclosures. The material is strong yet, not
brittle. Even repeated blows with a hammer will not cause the cover to chip, crack or shatter.
iLECSYS have the utmost confidence in the polycarbonate solution. A metallic enclosure would dent
and deform making the assembly compartment impossible to seal. An added paint or lacquer
coating would chip and/or crack, compromising the safety and Class II integrity of the enclosure.
iLECSYS are confident that the product will withstand normal service for many, many years and it
has been proved that only deliberate & wilful attempts to damage the enclosure can cause any
lasting damage. The solution offered is suitable for the most extreme & arduous installations and is
almost immune to accidental damage. We conclude that only deliberate vandalism can damage the
product to any real extent.
For any further information, please contact the undersigned.
Sincerely,
Mr. Adrian C. Dante.
Electrical Project Manager – Rail
Adrian Dante│ Electrical Projects │ iLECSYS │ Address: Unit 4, Tring Industrial Estate, Upper Icknield
Way, Tring, Hertfordshire, HP23 4JX
Phone: 08444 770 990 │ Main Office: 01442 828 387 │ Fax: 01442 828 399
Email: adrian@ilecsys.co.uk │ Website: www.ilecsys.co.uk │ Company Registration: 03426701
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