kurt.brinker
Member
We just got a call and one of our ML1100's has faulted. The error code is 0008H but i can't find anything dealing with this error. The unit is 14hrs away so i would like to get this resolved over the phone if possible. Thanks!
ML 1100 Fault
- Thread starter kurt.brinker
- Start date
rsdoran
Lifetime Supporting Member
Id 16301
Follow the guidelines in this document as a first step to resolve noise conditions and
0001H, 0002H, 0008H, 0009H
The recommendations made in the MicroLogix User Manuals, and The Industrial Automation Wiring
and Grounding Guidelines for Noise Immunity Document, Publication 1770-4.1-February 1998 are the actual
conditions under which the NEMA and CE certification tests are performed by Allen-Bradley.
If these recommendations are ignored, unknown problems, including unexpected faults, could occur.
The areas of concern if MicroLogix faults occur are:
Grounding
I/O
Power
Communications
Grounding
This is generally the most critical aspect of product installation with respect to noise immunity. A poorly
grounded system allows transient energy into the controller instead of diverting it away from internal
components. Chapter 2 of the above referenced MicroLogix User Manual discusses MicroLogix grounding
guidelines in detail. The following is a checklist that covers the most important aspects of grounding a
MicroLogix controller.
Ensure that there is a 6 inch or less length of 14 gauge wire used from the ground screw of the controller
to the ground bus. Or, if this is not possible, connect the ground screw of the controller to the mounting plate
or panel, making sure that this panel is securely grounded with a 14 gauge or heavier wire to the ground bus.
When AC power is supplied to the controller as a separately derived system through an
isolation/step-down transformer, you can connect it as a grounded AC system. For a grounded AC system,
connect one side of the transformer secondary (L2) to the ground bus. We strongly recommend using
grounded systems.
Follow local codes in determining whether to use a grounded system.
Inputs / Outputs
The suppression of conducted and radiated noise attributable to the arcing of inductive loads has been the
single most effective solution to improving MicroLogix noise immunity.
In addition, inductive load devices such as motor starters and solenoids require the use of some type of
surge suppression to protect the controller output contacts. By adding a suppression device directly across
the coil of an inductive device, you will significantly prolong the life of the switch contacts.
Refer to pages 1-8 through 1-10 of the above referenced MicroLogix User Manual and pages 15-18 of the
Industrial Automation Wiring and Grounding Guidelines for a complete description of I/O suppression
devices for A-B inductive loads connected to MicroLogix outputs. It takes energy from some source to create
electrical noise conditions. The most common sources of such energy are from turning inductive loads on/off.
Are inductive devices connected to MicroLogix outputs properly suppressed?
If not, suppression devices must be added as near to the load as possible.
For non-Allen Bradley loads, check the vendor's literature for the load being used for the correct
suppression devices. For A-B loads, refer to the following table for the correct suppression device:
Recommended Surge Suppressers for switching 24VDC inductive loads is a 1N4004 Diode
that is reverse wired across the load.
If a suppression device cannot be found, use the following: For 120VAC loads, Harris P/N V175LA10A.
For 240VAC loads, Harris P/N V320LA20A.
For detailed information on Allen-Bradley Surge Suppression devices please refer to the
Allen-Bradley Industrial Controls Catalog at http://www.ab.com/catalogs/.
AC (triac) outputs. RC network suppressers can damage triacs.
Power
The power supplied to the MicroLogix power supply and I/O is also a critical aspect concerning noise
immunity. Power considerations for MicroLogix controllers are discussed on pages 1-12 and 1-13 in the
above referenced MicroLogix User Manual. To increase power supply immunity to conducted noise,
perform the following:
Connect MOVs across the following AC input terminals on the controller: L1 and L2,
L1 and GND, and L2 and GND.
There is more, look up the document.
Follow the guidelines in this document as a first step to resolve noise conditions and
0001H, 0002H, 0008H, 0009H
The recommendations made in the MicroLogix User Manuals, and The Industrial Automation Wiring
and Grounding Guidelines for Noise Immunity Document, Publication 1770-4.1-February 1998 are the actual
conditions under which the NEMA and CE certification tests are performed by Allen-Bradley.
If these recommendations are ignored, unknown problems, including unexpected faults, could occur.
The areas of concern if MicroLogix faults occur are:
Grounding
I/O
Power
Communications
Grounding
This is generally the most critical aspect of product installation with respect to noise immunity. A poorly
grounded system allows transient energy into the controller instead of diverting it away from internal
components. Chapter 2 of the above referenced MicroLogix User Manual discusses MicroLogix grounding
guidelines in detail. The following is a checklist that covers the most important aspects of grounding a
MicroLogix controller.
Ensure that there is a 6 inch or less length of 14 gauge wire used from the ground screw of the controller
to the ground bus. Or, if this is not possible, connect the ground screw of the controller to the mounting plate
or panel, making sure that this panel is securely grounded with a 14 gauge or heavier wire to the ground bus.
When AC power is supplied to the controller as a separately derived system through an
isolation/step-down transformer, you can connect it as a grounded AC system. For a grounded AC system,
connect one side of the transformer secondary (L2) to the ground bus. We strongly recommend using
grounded systems.
Follow local codes in determining whether to use a grounded system.
Inputs / Outputs
The suppression of conducted and radiated noise attributable to the arcing of inductive loads has been the
single most effective solution to improving MicroLogix noise immunity.
In addition, inductive load devices such as motor starters and solenoids require the use of some type of
surge suppression to protect the controller output contacts. By adding a suppression device directly across
the coil of an inductive device, you will significantly prolong the life of the switch contacts.
Refer to pages 1-8 through 1-10 of the above referenced MicroLogix User Manual and pages 15-18 of the
Industrial Automation Wiring and Grounding Guidelines for a complete description of I/O suppression
devices for A-B inductive loads connected to MicroLogix outputs. It takes energy from some source to create
electrical noise conditions. The most common sources of such energy are from turning inductive loads on/off.
Are inductive devices connected to MicroLogix outputs properly suppressed?
If not, suppression devices must be added as near to the load as possible.
For non-Allen Bradley loads, check the vendor's literature for the load being used for the correct
suppression devices. For A-B loads, refer to the following table for the correct suppression device:
Recommended Surge Suppressers for switching 24VDC inductive loads is a 1N4004 Diode
that is reverse wired across the load.
If a suppression device cannot be found, use the following: For 120VAC loads, Harris P/N V175LA10A.
For 240VAC loads, Harris P/N V320LA20A.
For detailed information on Allen-Bradley Surge Suppression devices please refer to the
Allen-Bradley Industrial Controls Catalog at http://www.ab.com/catalogs/.
Be aware that an MOV should be used for the suppression of inductive devices connected to
AC (triac) outputs. RC network suppressers can damage triacs.
Power
The power supplied to the MicroLogix power supply and I/O is also a critical aspect concerning noise
immunity. Power considerations for MicroLogix controllers are discussed on pages 1-12 and 1-13 in the
above referenced MicroLogix User Manual. To increase power supply immunity to conducted noise,
perform the following:
Connect MOVs across the following AC input terminals on the controller: L1 and L2,
L1 and GND, and L2 and GND.
There is more, look up the document.
kurt.brinker
Member
OP
so its an electrical noise issue and not a programming issue?
rsdoran
Lifetime Supporting Member
That is what the AB knowledgebase offered on that code.
kurt.brinker
Member
OP
he cycled the power but it came back up as faulted.
rsdoran
Lifetime Supporting Member
Probably going to have to reload the program or at least access it, if possible, to clear the fault. I would still check if noise could be an issue.
kurt.brinker
Member
OP
we recently updated the program but it has been running for a few days now with no problems.
when you say software, do you mean the actual program?
all we changed was the scaling to an output card.
when you say software, do you mean the actual program?
all we changed was the scaling to an output card.
kurt.brinker
Member
OP
rsdoran said:
the operator is updating his rslinx right now and i am going to walk him through clearing the fault.
kurt.brinker
Member
OP
using the build in lcd he put it in program and then back into remote and the fault cleared. running ok now.
weird
weird
Mickey
Lifetime Supporting Member
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