DJ4G Type Mining Methane (Gas) Alarm and Power Off DeviceDetailed product description：

The DJ4G (formerly DJB4) mining methane (gas) alarm power-off device (hereinafter referred to as the power-off device) is mainly suitable for underground coal mines and other explosive gas (methane mixture, coal dust) occasions. It can be used on large and medium-sized mining equipment and other mechanical and electrical equipment underground to continuously detect the gas concentration in the airflow near the equipment. When the gas concentration reaches or exceeds 1.00% CH4, the power-off device immediately emits sound and light alarm signals. When the gas concentration reaches or exceeds 1.50% CH4, the power-off device immediately cuts off the power supply of the controlled equipment to ensure production safety. When the gas concentration drops to or below 0.50% CH4, the power-off device will automatically unlock (restore power to the controlled equipment) and continue detection.

The power-off device adopts high-performance thermal catalytic elements, large-scale integrated circuits, and new electronic devices, with digital display, stable performance, accurate threshold, rapid response, and high accuracy. The power-off device also has the characteristics of small size, low power consumption, simple applicability, and easy maintenance.

The DJ4G mining methane (gas) alarm power-off device consists of two parts: the host and the sensor. One host can be equipped with one or two sensors. When two sensors are connected, the gas concentration in two places can be detected separately. As long as the gas concentration in one place exceeds the limit, the power-off device will immediately cut off power. The maximum distance between the host and the sensor can reach 2.0 kilometers, with a weight of 5 kilograms.
The methane (gas) alarm power-off device is widely used in mining equipment such as explosion-proof rubber tired vehicles, support handling vehicles, coal mining machines, tunneling machines, continuous coal transport vehicles, forklifts, and anchor drills
After removing the explosion-proof casing, the DJ4G mining methane (gas) alarm power-off device can be directly installed in the control box of the coal mining machine or tunneling machine to trigger a power-off alarm The external dimensions after removing the shell are 120 * 80 millimeters  

Performance parameter table of DJ4G mining methane (gas) alarm power-off instrument

Project Name	Main technical parameters and performance
Explosion proof form	Exdil (explosion-proof and intrinsic safety type)
Rated working voltage	Ac127/380/660V (voltage adjustable/factory connected to 660V)
Total machine power	≤20W
measurement range	0～4% CH4
measurement error	When 0-1% CH4, ± 0.1% CH4, and 1-4% CH4, the true value is ± 10% CH4
alarm threshold	1.00% CH4。 Sound and light alarm
Power outage threshold	1.50% CH4， Sound and light alarm, power outage
Unlock threshold	0.50% CH4
Unlock Delay	1min
display mode	Three red digits display, one positive and negative sign display
alarm method	Red flashing, ≥ 85db police car sound
working method	continuous type
Host intrinsic safety power output	Maximum open circuit voltage: DC 18V Maximum load current: DC 600MA
sensor	Working voltage DC5V, maximum working current (single): 250mA
Capacity of power-off contacts	AC220V,5A，AC127V,10A，AC36V,15A， DC132V,10A，DC36V,15A，DC24V,20A
Overall dimensions	Host 200 × 160 × 98 sensor 130 × 85 × 43
Configure cables	Model: PUYVR; Name: Mining polyethylene insulated flame-retardant polyethylene sheathed signal flexible cable. Within 500 meters, 7/0.37; Within 1000 meters, 7/0.43; Within 1500 meters, 7/0.52.
Safety Sign Permit	Gas alarm power-off device: MFA080103 Low concentration methane sensor for coal mines: MFB080001