RSI installation contactors and RPI installation relays
Fig. 1: Installation contactors and relays
RSI installation contactors are capable of switching high powers not only for the AC-1 utilization category (lth to 63 A per one contact), but also for other utilization categories. Considering the high switched power the contacts must switch reliably which is at the costs of a loud click at the moment of the trip.
On the contrary, RPI installation relays are capable of noise-less switching, however at the costs of the switched powers which by far do not reach the values of the installation contactors (up to 16 A for AC-1).
For any applications of the devices other than within the AC-1 category the rated current values must be reduced both for the installation contactors and relays. For detail information on the maximum permissible number of loads please see the Minia catalogue or the Application Manual - Switching Devices.
As mentioned above, there is interdependence between switched power and noise. The devices can either make a "click" noise (at the moment of the trip/opening of the contact) or a "growl" noise (when switched). These noise properties define three sub-groups of installation contactors and relays:
Standard – RSI-A installation contactors
The coil control voltage may be AC only. The device makes clicks at trip and may make some "growl" noise when switched, caused by the line frequency. These contactors are mainly used for applications with no special requirements for noise-free operation.
Information on the type of the supply voltage (AC) in the type designation is indicated as the "A" character, e.g. RSI-25-40-A230.
Low-noise – RSI-X installation contactors
The coil control voltage may be both AC and DC. The device makes some "click" noise at trip, however comparing to the previous type it makes no "growl" noise due to rectification in the switched condition. These devices are recommended for applications with requirements for quiet operation, e.g. RSI-25-40-X230.
Extra low-noise – RPI installation relays
The coil control voltage may be both AC and DC in the case of the relay type with one or two switching contacts. The design with three switching contacts even allows connection of universal control voltage (AC 24 ÷ 230 V, DC 24 ÷ 220 V). The installation relays make no audible noise at trip or in switched condition. They are applied mainly in applications with requirements for extremely quiet operation, e.g. RPI-16-001-X230.
The Minia switching devices include five groups of products: