At MWM Elektro, we successfully completed a comprehensive modernization project for the 4L-2500/1000 hoisting machine operating in the “Wacław” shaft, which belongs to PGG S.A., KWK “Mysłowice-Wesoła” branch. The scope of the project included a complete overhaul of the power supply, control, and shaft signaling systems — all in accordance with current safety and energy efficiency standards.
Scope of the project
As part of the project, a new power supply and control system for the asynchronous motor drive of the hoisting machine was built from the ground up. The 1 MW motor is powered by a Rockwell PowerFlex 7000 frequency converter. The converter was installed in a new container located near the headframe and is supplied with 6 kV from field no. 2 of the R-03 switchgear. Additionally, field no. 25 was modernized — in both cases, new medium-voltage circuit breakers, controllers, and motorized actuators were installed.
A new auxiliary power switchboard R05 500/400/230 VAC was installed to supply control cabinets and auxiliary devices such as pumps, a fan, and an overhead crane.
Control system and logging equipment
The machine was equipped with a new control system, including a digital travel regulator based on the GRZ-08 solution and two AC500 controllers. Independently, an RG-4 recording device manufactured by MWM Elektro was installed to monitor the machine’s operating parameters.
The new operator’s cabin was outfitted with control panels and a computer for machine operation visualization.
The hoisting machine’s control system includes:
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an operator panel with gauges and control elements,
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the EPZSH-ah electropneumatic unit for dual-mode emergency braking,
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a safety relay circuit,
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a digital protection system based on PLC controllers.
The braking system also features a UWDWP device, which enforces additional air discharge from the compressed air safety brake system.
New speed limit switches were installed in the shaft to monitor the approach speed, along with switches to correct the position of the main conveyance and counterweight.
Signaling and communication system
A new intrinsically safe shaft signaling and communication system was implemented as part of the project. It is based on a PLC controller and the intrinsically safe ECHO-S wireless communication device. New signal stations were installed in the operator’s cabin, on the headframe, at the shaft collar, at shaft levels, and inside the hoisting conveyances.
The system uses two independent 230 V AC power supplies with backup power. Communication between stations is ensured via fiber optic cable. A new intrinsically safe communication console and five telephones were also installed at different levels of the hoisting shaft.
