While everyone was absorbed in
the landslide technological developments taking place in communication and
protection fields of Electrical Engineering, a silent revolution has taken
place in rubber mats laid in front of switchboards as a means of providing
safety for operators from electric shock. Gone are the days when mats looked
like foam beds! The new mats are so thin, that you would wonder whether they
would fly off if you switch on a man-cooler. Yet, these ultra thin mats are so
effective that the industry has switched over to them. What follows below is a
comparison between the old and new mats and a synopsis of their
characteristics.
| New Mats conforming to IS 15652:2006 | Old Mats conforming to IS 5424:1969 |
| Made of synthetic elastomer | Made of vulcanized rubber |
| Notified for use in India for all installations after Nov 1, 2007 through Gazette notification SO-2086 | Superseded from Nov 1, 2007 |
| High electrical insulation resistance 10,00,000 mega ohm when measured with 500 V meggar | Comparatively far lower insulation resistance |
| 100% shock proof under leakage current 10 mA | Unsafe in case of leakage of current. Tested from small electrodes as per IS: 2584-1963 the value of the leakage current is 160 mA per sq. mtr. |
| Fire Retardant | High fire prone & fire encouraging |
| No effect of
(a)
Transformer oil
(b) Acid
(c) Alkali
(d)
Diesel
|
Affected by all these |
| The withstand voltage is 36kV for one minute for 3mm mat | The withstand voltage is 15 kV for one minute |
| High dielectric strength 65KV for 3mm mat | Only 40 KV |
| Moisture proof | Absorbs moisture |
| Pastable type permanent fixed smooth trolley movement | Cannot be fixed permanently |
| Washable - Easy to clean | Not possible to clean |
| High tensile & elongation properties to withstand good mechanical properties. | No such properties as mat has to be removed for movement of trolleys |
The voltage class and thickness of mats are as follows
| New Mats conforming to IS 15652:2006 | Old Mats conforming to IS 5424:1969 | ||
| Thickness (mm) | Voltage class (kV) | Thickness (mm) | Voltage class (kV) |
| 2.0 | 3.3 | not less than 6.5 mm | not exceeding 3.3 kV |
| 2.5 | 11 | ||
| 3.0 | 33 | ||
| 3.5 | 66 | ||
