Batteries are labeled with amp-hour capacity, so if there is a heavy load in terms of remote heads and exit lights, calculations may be in order. If the box will hold two batteries, it’s a good policy to use both. The letters R, A and G are used in addition to swatches of colour, so that the system can be used by colour blind readers. Click here to read more about one of the most powerful and versatile controllers on the market! However, there is neither mention of a specific time interval nor what the test should entail. This minutia matters, in that it may determine whether the Sheffield project is just barely in compliance or just barely too loud at times; after all, limits are limits.