Explosion-proof pressure difference relays are meant for electrical switching when pressure difference reaches the set values (actuation setpoint) and switching back the contact group when pressure difference changes by the differential value.
- relays have one normally open and one normally closed contact. Contacts provide switching of active and inductive loads with (1 ... 100) mA current at (20 ... 30) V voltage. The number of activations is not more than 105 under these loads;
- mass-produced, have "1ExdIIBT4" marking of explosion protection, conform to GOST 12.2.020-76, GOST 22782.0-81, GOST 22782.6-81;
- according to the degree of protection against dust and water - . IP65 according to GOST 14254-80.
|Range of activation setpoints||MPa||(0-0,015...0-0,0025)...(1,0-2,5)|
|Operating temperature range||°C||-50...+70|
Relays have two versions and modifications, different in the range of activation setpoints (see. Table below).
Version 1: relay is actuated (closure of contact 1-2) when the pressure difference increases up to the actuation pressure [Pact]. Relay is armed (closure of contact 1-3) when the pressure difference goes down to value (Ract - D), where D is differential. Differential is the absolute difference between the actuation pressure [Pact] and the arming pressure [Parm]. The initial state for all relay versions is the state, when the pressure in the working volume of relays is equal to the atmospheric one.
Version 2: relay is actuated (closure of contact 1-3) when the pressure difference goes down to the actuation pressure [Pact] after preceding pressure increase up to the arming pressure [Parm] (closure of contact 1-2) that is greater than [Pact] by the value of differential D. Differential is the absolute difference between the actuation pressure [Pact] and the arming pressure [Parm].