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This Policy is complete waiting Field Service, Engineering, and EHSS approval.
Purpose
Purpose
The purpose of this procedure is to establish the minimum requirements for setting up the Auto Loading Page on Gas Engine Drive units in the LOGIX control panel. The procedure applies to all Gas Engine Drive LOGIX panels equipped with the Auto Loading feature option. This procedure is to ensure the proper set up of the Gas Engine Drive Auto Loading Page to ensure full PLC control of RPM and loading in the LOGIX panel as laid out in this procedure.
Procedure
Procedure
This procedure applies to all Gas Engine Drive units that are equipped with the LOGIX panel that has the Auto Loading Page Control Mode option currently in service in the Field, Test Loop, at a Repair Shop, or in Storage Yards. Flogistix Service Technicians will perform the set up of the Auto Loading Page in the LOGIX panel as laid out in this procedure according to this procedure.
Before any work is performed a JSA needs to be done according to Flogistix procedure along with any Customer requirements before any work is started.
The Auto Loading function will increase or decrease engine speed, load or unload poppet valves as needed per the setpoints in the Auto Loading function.
To set up the Auto Loading Mode settings in the LOGIX panel you must first be logged into the LOGIX panel under an Mechanic Level or higher
To set up the Auto Loading functions: From the Home Page at the bottom of the page touch the Settings Button , at the Settings Page touch the Auto Loading Page, that will be at the top of the Settings Page.
Example above shows Auto Loading page
Max Discharge Pressure set up:.
Under the SetPoint Column, touch the yellow button to the right of Max Discharge Pressure.
In the example below the Max Discharge Pressure is highlighted in Red
Then enter the desired Max Discharge Pressure that you want the compressor unit to start slowing down at. This setting should be less than the kill setting entered from the Home page.
Next, enter a deadband value highlighted in Red in the example below.
The deadband is the allowable error above and below the setpoint.
If the speed can maintain pressure within the deadband, the poppet valves will not act.
If the pressure is above the setpoint plus deadband, or below the setpoint minus deadband, speed changes happen normally, but poppet valves also begin to act as well.
Min Suction Pressure
If Home screen is set to Auto the Min Suction Pressure boxes will be visible in Yellow meaning the PLC is controlling from Min Suction Pressure and Max Tank Vapor Pressure will be visible in Blue meaning the PLC is not controlling off of Max Tank Vapor Pressure.
Under the SetPoint Column touch the yellow button to the right of Min Suction Pressure.
Then enter the desired Suction Pressure that you want the compressor to try to start slowing down at to maintain the desired Suction Pressure.
This setting should be greater than the kill setting entered from the main page.
Next touch the yellow box under Dead Band and then enter the desired Dead Band Pressure.
If the speed can maintain pressure within the deadband, the poppet valves will not act.
If the pressure is above the setpoint plus deadband, or below the setpoint minus deadband, speed changes happen normally, but poppet valves also begin to act as well.
Max Eng. Manifold Pressure
Under the SetPoint Column touch the yellow button to the right of Max Engine Manifold Pressure.
Then enter the desired Engine Manifold Pressure that you want the engine to start unloading.
Next touch the yellow box under Dead Band and then enter the desired Dead Band Pressure.
** Special note that the Max Engine Manifold pressure on a naturally aspirated engine is a negative number.
If the speed can maintain pressure within the deadband, the poppet valves will not act.
If the pressure is above the setpoint plus deadband, or below the setpoint minus deadband, speed changes happen normally, but poppet valves also begin to act as well.
Most common set pressure for the manifold pressure on a naturally aspirated engine is -4.0.
This setting should be less than the kill setting entered from the main page.
Max Tank Vapor Pressure
If Home screen is set to VRU the Max Tank Vapor Pressure boxes will be visible in Yellow meaning the PLC is controlling from Tank Vapor Pressure (remote Transmitter) and the Min Suction Pressure will be visible in Blue meaning the PLC is not controlling off of Min Suction Pressure.
Under the SetPoint Column touch the yellow button to the right of Max Tank Vapor Pressure.
Then enter the desired Tank Vapor Pressure that you want the compressor to try to start slowing down at to maintain the desired Tank Vapor Pressure.
This setting should be greater than the kill setting entered from the main page.
Next touch the yellow box under Dead Band and then enter the desired Dead Band Pressure.
If the speed can maintain pressure within the deadband, the poppet valves will not act.
If the pressure is above the setpoint plus deadband, or below the setpoint minus deadband, speed changes happen normally, but poppet valves also begin to act as well.
Min Eng. J.W. Temperature
Touch the yellow box beside Min Eng J.W. Temperature.
Enter the minimum engine jacket water temperature for warm –up.
This is the minimum temperature that the engine will need to achieve for a warm up temperature before any auto-loading functions will become active.
Max Eng. J.W. Temperature
Touch the yellow box beside Max Engine J.W. Temperature.
Enter the desired maximum temperature that the engine needs to run at before activating the unload function.
This is the Maximum temperature of the Engine when the Auto Loading will start to unload poppets to keep from overheating.
This temperature setting should be set below the Engine Jacket Water High temperature shutdown setpoint.
Loading Time delay
Once all loading permissives are achieved, the Panel displays all Green lights on the Loading Page, indicating it can increase load /speed.
This is the time in seconds that it must remain in the loading permissive status before loading the compressor.
If any of the targets go to neutral (neither light on), poppets will not act. If any of the targets go to unload (red light on), poppets will unload and speed will be reduced (except for temperature control).
Loading Valve Pulse On Time
Smaller steps from each pulse of the poppet valve is the desired control, but they are operated by relays and valves with mechanical moving parts.
If the pulse is On for very long, it could load the poppet valve all the way with one pulse. For this reason the Loading Valve Pulse On Time should be set at a very time.
The shortest time possible is 0.1 seconds for each pulse. This maybe enough time to load the poppet in progressive steps for desired load control
Loading Valve Pulse Off Time
This is the time between pulse signals to either Load or Unload the Poppet Valves.
Some time delay between pulses allows changes from the poppet loading or unloading to affect the system and reach the target without as much overshoot.
Loading Valve Pulses
When the PLC determines that poppet valves should act, either loading or unloading, the valves are sent a short burst of pressure.
The pressure source may be discharge gas or compressor oil and is sent to the poppet valve by a solenoid valve.
To allow small loading steps, these valves are pulsed on and off very quickly. The movement from each pulse will vary, so the PLC will pulse the defined number of times before moving on to the next valve.
The PLC when in Full control of the Loading valves reacts in this sequence.
Once the first Loading Valve is fully loaded from 5 pulses it moves to the next Loading Valve.
** On the Auto Loading feature if the panel is set to Load fast it will also Unload fast or if Loading slow it will Unload slow.
The loading function can not be separated like Loading slow but Unloads fast.
When the PLC is in Full control of the Auto Loading Feature look at the Load Permissive Green & Red lights on the right of the Auto Loading Page.
If the Load Permissive Lights are all Green as in the Sample below the unit should be running at the highest speed of either Max or at Setpoint, and if equipped with Load Valves all Load Valves should be loaded.
When the PLC is in Full control of the Auto Loading Feature but Engine RPM may not be running at highest RPM of Max or Setpoint look at the Load Permissive Green & Red lights on the right of the Auto Loading Page.
If the Load Permissive Lights are Not all Green as in the Sample below and a Red Light is on the unit could be running at the low speed setpoint.
What ever Red light is illuminated is the Pressure that is below the Setpoint and Deadband Permissive not allowing the unit to speed up and fully load.
If there is not a Green or Red Load Permissive light On the unit will be running at a desired speed to maintain one of the desired pressure setpoints that is not illuminated. No Picture Sample
Responsibilities
Responsibilities
Management - Management is responsible for implementing, supporting, and enforcing the requirements of this procedure to their respective locations/area.
EHSS - Responsible to assist in the implementation of this procedure and to review for effectiveness.
Employees, Contractors, Vendors, ETC. - Are responsible to follow the requirements outlined in this procedure and ask for assistance
Scope
Scope
This procedure applies to all Flogistix Gas Engine Drive compressor units equipped with a LOGIX control panel with the Auto Loading feature option and are applicable to all Flogistix employees, contractors, and temporary employees.
Hazards
Hazards
Employees should be aware that units could contain flammable and toxic gasses. Potential for the possible hazards of gas ignition or fire, hot surfaces & fluids, rotating equipment. Risk of possible concentration of H2S. Hazardous gases could be in the units pressure vessels, cooler, or associated piping and risk of inhalation of hazardous gas fumes.
Safety
Safety
All Personal Protective Equipment (PPE) for normal Field Mechanical duties apply for this procedure.
Four Gas Monitor, which is outlined in the Flogistix EHSS Manual, PPE Section 8, Procedure 8.3
This procedure applies to all units in service in the field, at a service shop, or in any storage yard.
Insure Flogistix personnel have proper safety certification or site orientation if required by the Flogistix Customer.
Insure Flogistix personnel adhere to all Customers safety practices.
Training
Training
All employees shall be initially trained on the following topics:
Employee Personal Protective Equipment (PPE)
Lock Out Tag Out (LOTO) procedure according to Flogistix policy
Emergency and First Aid procedures
Methods and Observations that may be used to detect the presence or release of a hazardous chemicals or gas in the work place
Basic LOGIX panel training
Tools & Equipment Required
All employees performing this procedure shall be required to have the listed tools to perform job tasks:
All required PPE according to Flogistix Safety Policy
Approvals
Field Service approved by:
Date:
Engineering approved by:
Date:
EHSS approved by:
Date:
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