4. Routine maintenance, inspection and operational testing of the emergency generator and associated. components must be overseen by a properly trained person [see MSFC(07), Sec. 604.5; NFPA. 99(99), Sec. 3-4.4.1.1(b)3; NFPA 110(99), Sec. 6-4.7; NFPA 110(02), Sec. 8.4.7].
If rain and wet roads are a concern, you should consider replacing your tires when they reach approximately 4/32 of remaining tread depth. Since water can't be compressed, you need enough tread depth to allow it to escape through the tire's grooves.f two of your tires have a lot of remaining tread depth, but you need to replace the other two because they were damaged or have worn out, you should replace them with a pair of tires that come as close as possible to matching your existing tires.
The tread depth groove in the tyres will tell you when your tyres are at the bare legal minimum of 1.6mm, ideally you should change your tyres earlier. The best way to check you tread depth is to buy a tread depth gauge.The gauge will give you the exact amount of tread remaining and will a lot more accurate.ost tyres now also have a depth indicator as shown in the picture above. The depth indicator is placed around the tyre within the groove. This is an easy way to check your tread depth. Once this groove indicator levels off with the top the tread the tyres are at 1.6mm.