KTT3-utility of broadcasting telephone intrinsically safe mine of broadcasting communication, the signal contact sound and light alarm device, suitable for coal mine gas and coal dust explosion hazardous environment, but also for coal, metallurgy, chemicals, building materials , transportation, electricity, food and other industries ground harsh environments. The telephone can self-expanding broadcast communications and the RBI signal contact system, can also be included in the the DPCs exchange communication system through an interface device. Accept an external control signal, audible and visual alarm signal for the device start-up notice or alarm. 2 Features 2.1 phone with a four-core cable Unicom (with charge), to form an independent half-duplex communications, alarm and RBI signal contact system of broadcasting across the board; 2.2 interface can be included in the the DPCs exchange communication system, and can be set a phone call; the 2.3 any phone to accept an external control signal can be audible and visual alarm signal on the same line telephone, can be used to start notice of the control system or other alarm; 2.4 built-in float battery pack, external power supply is temporarily interrupted, the communication is not affected; the 2.5 float battery pack built-recoverable insurance device used as a short-circuit protection, and to ensure that the safety performance; 2.6 low voltage monitoring to ensure communication systems work; 2.7 rugged steel enclosure, excellent protective properties; 2.8 high degree of protection of the cable connector, easy on-site installation wiring. 3 main technical indicators 3.1 system capacity and communication distance: 25, 5Km, phone uniformly distributed (mine signal cable PUYVR 1 × 2 × 7/0.43 +1 × 2 × 7/0.30) 3.2 external charging: DC15V ~ 27V mine 3.3 internal power supply intrinsically safe power supply (KDW9A KDW15 ZBK mine intrinsically safe power supply): 6GNY0.6Ah nickel-cadmium battery pack (built-recoverable insurance device, Rmin = 0.25 Ohm, Rmax = 0.40Ω, Imax = 0.75A ) 3.4 Alarm signal: tone alternating signal, low frequency 750Hz ± 100Hz, high frequency 1000Hz ± 100Hz alternating time 0.5 to 1S (alarm control input must be connected to intrinsically safe circuits) 3.5 RBIs signal: 750Hz ± 100Hz 3.6 RBI single tone signal alarm sounds: not less than 90 dB 3.7 alarm control signal: DC current (10mA) or potential-free contacts 3.8 Dimensions (L × W × H): 360mm x 165mm x 200 mM 3.9 Weight: 10.5kg 3.10 Enclosure protection class: IP65 3.11 Explosion-proof type: Mine intrinsically safe Exib I 3.12 outlet allows cable diameter: 12MM 3.13 connector allows cable diameter: 7 to 8.5mm