THE STORY OF THE P&H MODEL 2800

By     Richard “Chubby” Czubkowski

1987 ---- 2800XPA      P&H  ELECTROTORQUE -----------------






The functional control of the 5700DR was designed using a Programmable Logic Controller PLC. A PLC was designed for the XPA to replace the logic relays as previously used. The added feature made it possible to add indicators for fault, running alerts etc.


Improvements -----------

PMD, located in the operator’s station and one located in the Electronic room in the PLC Cabinet. The PMD was programmed to give operational faults and trouble  correction information.

 The fixed banks were reduces down to one. The switched banks were sequenced by  control, to allow a ½ bank being switched on between full banks.  VAR excursions  were reduced.  

The performance curves were enhanced by taking advantage of the peak commutation capability of the improved K frame motors.                                                  


1992 ---- AC DESIGN ------


Another engineering collaboration with ABB (ASEA/BBC) was started to design the next AC shovel control. Inverter technology, techniques and devices to control the Adjustable Frequency Systems had advanced. ABB proposed a GTO system. The packaging of the frequency inverters, controls and rectifiers were to be manufactured and designed jointly by P&H and ABB.


There was a difference in philosophy of the control components between ABB and P&H engineers assigned to the project.  ABB had proposed there system using GTO.  There were other devices similar to the GTO which were in their infancy. The IGBT was firmly in the picture with Siemens and their system running on BI shovels. ABB did not have a suitable IBGT system for shovel use.


A few vendors were looked at.  Most were IGBT systems which seemed suitable for shovel service. P&H engineering could not agree on a system .The cost of the ABB GTO system was much greater as compared to the DC system.  The project ended in 1994.

 


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MODEL

CAPACITY

LOAD RATING

YEARS  MFG.

2800XPC

39-48 CY.

135 sT

2006

MODEL

CAPACITY

LOAD RATING

YEARS  MFG.

2800XPA

28-32 CY.

120sT

1988

MODEL

CAPACITY

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YEARS  MFG.

2800XPC

39-48 CY.

135 sT

2010

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XPC  CENTURION  ELECTRICAL  AC  CONTROL SYSTEM ------






The CENTURION control system basically remains the same as the DC version. The main changes to the shovel are the AC motion motors and the Variable Frequency Convertor, AC IGBT Drives on the counter weight box.  


Features of the IGBT system -----



XPC  CENTURION ELECTRICAL DC CONTROL SYSTEM ------






Feature of the 2800XPC ------

 


Advanced control technology ---–



The shovel has multiple options for local and mine site specific conditions in the following areas:


Technology



XPB  ELECTROTORQUE -----






The need for a larger capacity shovels and design techniques, allowed the XPA machines to upgrade to the XPB rating. The philosophy of manufacturing was upgraded.  Shovels manufactured were almost completely assembled and custom wires in the shop. Then the shovels were disassembled, wiring and mechanical assembles, for shipping. The shovel at the customers’ site was re-assembled.


The XPB was resigned to facilitate partial assemble in the shop and modularize assembles for ease of field erection. An air conditioned Electronics Room, under the Operators room, housed all the sensitive electronics and provide a clean environment for personnel. The power electronics, Convertors, RPC, were placed on the counterweight box to facilitate better ventilation filtered air.  The Main Transformer and HV Switch gear were located on the right platform. These three assemblies could be shipped intact for ease of field assembly.


The custom wiring was replaces with pre-made wiring harnesses and plug and sockets type wiring. The power cables were also pre-cut and lugged to facilitate field wiring. These changes reduced wiring errors in field erection.   


Improvements ---------

 The hoist and swings bridges were now rated at 1320kw @ 600vac from 1020kw @ 600vac.


DIGITAL CONTROLS -----


The initial XPBs used the analog Combi-flex control modified by P&H. In early 1995, an engineering decision was made to explore a digital control. The main objective was to merely replace the Combi-flex cards and racks with digital control modules, keeping the PLC and peripheral equipment the same. The current philosophy was, change by evolution and not wholesale innovation.   A decision was made to go with a Cleveland firm, AVTRON. They had the reputation of being the retro-fit kings and private labeled supplied controls to a wide array of industries. P&H partnered with AVTRON to private label the modules.


The Control Cabinet was redesigned by P&H to accommodate the digital modules with all the necessary feedback and control power. Many former components were simplified especially in the feedback circuits.


The same modules called an AFM, AVTRON Advance Firing Module, were designed with built hardware that could be used for all motion motor control, motor field control and RPC Control. Five AFM modules are use used to control all shovel motions and RPC functions. The modules contain the control intelligence and the pulse generation for the motion armature and field convertor and the RPC switches.


Specific Firmware (i.e. Software) is loaded to configure the AFM to function as a;


The modules also provided;

 

The AFM Specific Firmware is loaded at commissioning. Allowed parameter changes are made through a PC, with supplied software, or a display on the modules. The display is also used to display various parameters and faults.


AVTRON supplied the AFM and the entire Control Cabinet assembly. This system was used on Models 4100A, 4100TS, 2800XPB and 4100BOSS from 1996 to 2003.  The digital control from AVTRON was unofficially called and labeled P&H .ELECTROTORQUE- PLUS


In conjunction with the digital control a MMI (Man Machine Interfaces) or GUI (Graphical User Interface) was added in the control cabinet and Operator’s cab.


Twenty-five AVTRON systems were applied to 2800XPBs, 4100As, 4100TSs and 4100BOSSs.  The AVTRON system was well accepted by P&H customers.  It fulfilled, the than philosophy, of merely replacing the analog control with a digital control with no significant cost penalty.   


Around 1999, the Electrical Engineering Department was separated into R&D and Production.  P&H Management decided to revert back to a partnership with ABB for a Digital control package. The new emphasis was on innovation and complete control of the shovel systems and options by P&H. The last Control Cabinet, manufactured by AVTRON with the P&H/AVTRON AFM modules, was built in 2003. .



ABB DIGITAL DC CONTROL -----


CENTURION ELECTRICAL CONTROL SYSTEM ------


The latter XPBs were manufactured with the first “Centurion” control from ABB.


The drive system is comprised of two major components;


  


The RPC is a “standalone” system that has its own controller (PLC). It also incorporates bank rotation.  



The Centurion electrical control system provides superior performance, monitoring, and data integration capabilities. The supervisory controller, with direct integrated communication with the motor drives, allows precise motor control and fast cycle times. Real-time multi-tasking capability means optimal machine logic sequencing, monitoring, and control.


The Supervisory Controller eliminates the former PLC functions. The I/O system uses the Profibus communication protocol for seamless integration of all shovel subsystems. Low-voltage 23V DC I/O drop points feature open- and short-circuit detection for improved diagnostics and troubleshooting.


The graphical user interface features intuitive, icon-based screens that display vital information, including shovel status, troubleshooting information, and optional production monitoring data and operator feedback system, transforming the data into valuable knowledge, including KPI (key performance indicator) dashboards, graphical analysis tools, predictive modeling, and reporting tools.


1987----- 2800 XP AC ELECTROTORQUE -----------------






P&H, for years, had the only DC Convertor system on shovels. BI went to an AC system skipping static DC systems. Although P&H was the shovel leader, pressure was put on to complete with the AC systems.


A joint engineering venture, with ASEA, was started to make an AC system. The Frequency Convertor was modeled after ASEA„s train systems.  


The Frequency Converter system was a Thyristors Inverter scheme. In 1987 the first machine was put into operation. It was a learning curve for engineering. The control was sensitive to noise especially static electricity discharges.  A wire Screen was put on the glass window on the control cabinet.  Numerous noise techniques were employed to lessen the susceptibility to noise.


The Thyristor assembly was attached by a stab assembly for easy unit removal.  Due to the vibration and shock of the shovel, the assembly tended to arc under high current, destroying the Thyristor or the entire assembly.  


The AC control produced transient motor torques during faults which resulted in structural mechanical failures.  The entire system required too much care.  Engineering had to work through both mechanical and electrical short comings. The customer and P&H service were ill prepared for this control.  


Another machine, a 2800LR coal loader, was reluctantly brought in 1989. The same problem, to a lesser degree, also plagued this machine.  P&H had to purchase, not only the shovel system but also spare components because ASEA was obsolescing the present AC system. The adventure was very costly to P&H, in money and time to engineering and service personnel.  


Because of the frequency inverter design, expense and rapid expansion of new technology, it was not practical to keep the systems running.  One of these machines was converted to a DC system and the other used for spare mechanical parts.

Improvements -----------


MODEL

CAPACITY

LOAD RATING

YEARS  MFG.

2800XP

28-32 CY.

120sT

1987-1989

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MODEL

CAPACITY

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YEARS  MFG.

2800XPB

44-46 CY.

130sT

1992

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