Diversity
(work in progress)
Diversity in this context is all about how one establishes the maximum demand for an electrical installation or an electrical circuit. The guidelines shown here are some of those as presented in the On Site Guide. Note however that these are just that - guidelines. They are based on statistical probabilities and typical usage. As a circuit or installation designer you may choose to make less flexible assessments of current demand based on your knowledge of the actual installation.
Note also that the figures presented here are for domestic properties only.
Allowances for Diversity
| Purpose of circuit | Diversity applicable (domestic) | Notes |
|---|---|---|
| Lighting | 66% of total current | |
| Heating and Power | 100% of total demand up to 10A, + 50% of the remainder. | Where space heating is connected to a general purpose power circuit. |
| Cooking appliances | 100% of total demand up to 10A, + 30% of the remainder. | Add a further 5A if a socket is fitted to the cooker point. |
| Water heaters (instant) | 100% of first appliance, 100% of second, and 25% of any remaining appliances. | |
| Water heaters (storage) | No diversity allowable | |
| Under floor heating | No diversity allowable | |
| Storage Heaters | No diversity allowable | |
| Standard Circuits | 100% of current demand of largest circuit. + 40% of demand for every other circuit. | These are standard final circuits as described in appendix 8 of the OSG |