Connecting the system to the mains requires a competent electrician with 18th Edition Electrical Qualifications. The Automist circuit should be clearly labelled (a sticker is provided for this purpose). Automist requires an independent 230V a.c. / 50Hz electrical supply, not shared with other unrelated devices. The Automist system, fire detection and alarm system may use this circuit, which must remain powered in the event of a fire. Power to Automist must be provided via an unswitched fused connection unit (FCU). Automist should be supplied using FP200 cable or better, ideally inside conduit or protected 50mm deep within a wall, and with RCD or RCBO protection. RCD or RCBO protection may be required, however, by applicable electrical installation regulations, in which case the circuit design must be such that the operation of any other RCD, RCBO or safety device does not affect the operation of Automist. Typically, on a split-load board, Automist should be connected to the non-protected side of the board. Where there are no spare ways in the existing consumer unit, or there are no available non-RCD protected ways in the existing consumer unit, the electrician may wish to use a Henley Block to provide new tails to a second distribution board (typically a 2- or 4-way unit) with no spare ways for future use.
The Automist unit presents a part-inductive load and therefore only type “C” breakers are suitable. Because Automist Smartscan is often used for life safety applications, installers should add a suitable safety margin to the MCB ratings. The circuit supplying a single Automist unit would commonly be protected by a type ‘C10’ or ‘C16’, for example, or ‘C20’ / ‘C32’ for two Automist Smartscan units. This should be on a C-type breaker, on an RCBO or a RCD protected circuit. The RCD circuit should protect only the Automist system and not be incorporated with any other circuit in the property. If the consumer unit is located in the protected area it should be protected by an electrical cover. However, if the consumer unit is in the protected area and has a metal enclosure complying with 18th Edition IET Wiring Regulations to BS 7671 2018; it does not require the addition of an over box to meet BS476 Part 22 (1987) and EN1364 (1999). If the electrical installation is required to follow BS 8458, the stipulations of that standard should be adopted; in particular, it may require the use of fuses rather than MCBs as well as a “separately fused connection taken after the meter and from the supply side of the domestic or residential fuse box”.