Reyrolle type C21 (Duo-bias) Electromechanical relays

[Mhobi]

please I need the datasheet/installation manual for the Reyrolle type C21 (Duo-bias) Electromechanical differential relay. I need to identify the terminal M1, M2, L and the R1...R8 terminals. which is for the primary CT, secondary CT, Neutral, trip terminal and alarm?

 

[DiscoP]

I don't have it, but you could try your local Siemens agent. Siemens bought Reyrolle's relay group out a few years ago.

I think the C21 is called a "mono-bias" relay, then they come out wth the 2C21 and 4C21 which were "duo-bias" versions, so might be worth knowing exactly which one you need.

Siemens Reyrolle still use the Dueo-bias brand name on their modern diff relays.

 

[Mhobi]

Actually the differential relay is the three number electromechanical(one for each phase) reyrolle type C21 with duobias written on it. I have searched the Siemens site but could only see the recent digital duobias-M relay and not the electromechanical type.

 

[mLp85]

Hi Mhobi,

I have a 'leaflet' that you may find some answers in. Good luck.