Model KTA7 Mine-used Safe Coupler is equipped products for Model KTH8 I.S. Automatic Telephone and Automatic Telephone with Anti-noise, can connect with surface program-controlled exchangers or dispatching exchangers to establish Intrinsic Safety dispatching and communication system with automatic dialing for mine underground.
Function and Features
Convert Non-intrinsic Safety ring-current, direct current to Intrinsic Safety ring-current and direct current;
Bidirectional transmission of voice signals;
Transfer dialing signals of intrinsic safety telephones (T/P compatible).
Technical Parameters
Explosionproof Type: Mine-used general type and intrinsic safety type, marked as [Exib] I
Input at Non-intrinsic Safety Side:
Max. input DC voltage is 60V, maximum input DC current is 60 mA;
Max. input voltage of ring-current is 90 V, max. input current of ring-current is 100 mA
Input at Intrinsic Safety Side:
Maximum open-circuit DC voltage is 60 V, maximum short-circuit DC current is 29 mA;
Maximum open-circuit voltage of ring-current is 56 V, maximum short-circuit current of ring-current is 34 mA
