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iGUARD Troubleshooting
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Mechanical Engines:
- Will not allow a manual start
- Engine will not crank
- Engine cranks but won't start
- Engine cranks, starts and then stops almost immediately
- Engine cranks starts and runs, but shuts down after awhile
- Won't show engine parameters
- Controller shuts down for various reasons
- Controller has shutdown, and won't restart
- Multiple senders for the same parameters
- Engine parameters are consistently wrong
- Engine parameters are erratic
- Problems with Run/Idle mode
1. Will not allow a manual start
a. Is security level set to prevent all manual starts?
b. Is security level set to prevent a mode change from AUTO to MANUAL?
c. Is one of the digital inputs programmed for a manual start switch? - This always overrides the front panel keypad
d. Did engine shut down last time on an error?
i. Press "ACK ALARM" several times, until controller indicates that it has been reset
ii. Alternately, cycle power to the controller
a. Check the status/Warning screen (Press the BACK/NEXT key)
i. Are there any "NS" warnings active? If so, clear them by correcting the problem indicated
b. Did engine shut down last time on an error?
i. Press "ACK ALARM" several times, until controller indicates that it has been reset
ii. Alternately, cycle power to the controller
c. Is the emergency stop switch activated? (J8) This de-powers the relays
d. Is there a connection from relay K2 (The default crank control relay) to the starter motor slave relay?
e. Is there power (+V battery) to the common of the K2 relay?
f. Is the crank relay still the default relay? (K2)
3. Engine cranks but won't start
a. Check the Status/Warning screen (Press the BACK/NEXT keys) for any faults or information that might have to do with starting/running the engine
b. Is there a connection from relay K3 (The default fuel control relay) to the fuel solenoid/governor?
c. Is there power (+V battery) to the common of the K3 relay?
d. Is the fuel relay still the default relay? (K3)
e. Does the engine have fuel?
f. Did the engine run out of fuel and shutdown last time?
g. Is there an air damper shutdown in the system? - Is it tripped?
4. Engine cranks, starts and then stops almost immediately
a. Check the status/Warning screen (Press the BACK/NEXT key)
i. If there are warnings/alarms showing take the necessary corrective actions (see also #7 below)
b. Check the fuel level and the rest of the fuel system
c. Check the electrical connections to the fuel relay and verify that they are secure
5. Engine cranks starts and runs, but shuts down after awhile
a. Check the status/Warning screen (Press the BACK/NEXT key)
i. If there are warnings/alarms showing take the necessary corrective actions (see also #7 below)
b. Check the fuel level and the rest of the fuel system
c. Check the electrical connections to the fuel relay and verify that they are secure
6. Won't show some engine parameters
a. Mechanically fueled engines will not:
i. Show % load
ii. Drive % load analog gages
iii. Show parameters that are not specifically instrumented - i.e. If you want oil temperature displayed, you must install a sender to measure the oil temperature, and program one of the analog channels to use it
iv. Drive analog gages for parameters that are not specifically instrumented
b. The iGCON software tool allows control over which parameters, the order and the display style. Please contact the source of the controller about getting the displays arranged to your liking, or contact Murphy technical services (918) 317-4100
a. Low oil pressure
i. Check the shutdown history to see the value of the parameter at shutdown. Verify that this is the correct value for your application
ii. Check the Warning/Status screen for currently active errors and warnings. Take the necessary steps to correct the warnings and/or errors
iii. Sometimes, a loose wire can cause a shutdown that will masquerade as a totally different problem. Check that the wires to the senders are connected securely.
iv. Check that the return wire from the sender actually comes back to the iGUARD, and is not in fact grounded to the frame.
b. High engine temperature
i. Check the shutdown history to see the value of the parameter at shutdown. Verify that this is the correct value for your application
ii. Check the Warning/Status screen for currently active errors and warnings. Take the necessary steps to correct the warnings and/or errors
iii. Sometimes, a loose wire can cause a shutdown that will masquerade as a totally different problem. Check that the wires to the senders are connected securely.
iv. Check that the return wire from the sender actually comes back to the iGUARD, and is not in fact grounded to the frame.
c. Sender open/shorted
i. Check the Warning/Status screen for currently active errors and warnings. Take the necessary steps to correct the warnings and/or errors
ii. Sometimes, a loose wire can cause a shutdown that will masquerade as a totally different problem. Check that the wires to the senders are connected securely.
iii. Check that the return wire from the sender actually comes back to the iGUARD, and is not in fact grounded to the frame.
d. Underspeed
i. Check the shutdown history to see the value of the parameter at shutdown. Verify that this is the correct value for your application
ii. Verify that the number of gear teeth is set correctly
iii. Check that the magnetic pickup is installed correctly
iv. Verify that the output from the magnetic pickup is at least 2VRMS
v. Check that the magnetic pickup is free from iron/steel filings and other mechanical contamination.
vi. Check that the signal wire from the magnetic pickup to the controller is intact - no nicks, cuts, or crushing of the cable - and the shielding is intact.
vii. Verify that the magnetic pickup wires are not run in conduit with the AC wiring
viii. If the set is spark ignited, verify that the spark plugs and spark plug wires are resistive type, and the ignition is properly grounded.
ix. Even though the iGUARD passes the EC requirement for immunity to radiated noise, beyond a certain point - *very* strong field strengths - EMI/RFI can still cause problems. Turn off radio gear and try running again.
x. Check that the governor is correctly set for this application. Sometimes a governor with too little overall gain, (or some other aspect of the governors PID loop set wrong) will reach operating speed too slowly at startup or will recover too slowly from a block load event and the underspeed bubble timer will expire before the RPM climbs back above the setpoint
e. Overspeed
i. Check the shutdown history to see the value of the parameter at shutdown. Verify that this is the correct value for your application
ii. Verify that the number of gear teeth is set correctly
iii. Check that the magnetic pickup is installed correctly
iv. Verify that the output from the magnetic pickup is at least 2VRMS
v. Check that the magnetic pickup is free from iron/steel filings and other mechanical contamination.
vi. Check that the signal wire from the magnetic pickup to the controller is intact - no nicks, cuts, or crushing of the cable - and that the shielding is intact
vii. Verify that the magnetic pickup wires are not run in conduit with the AC wiring
viii. If the set is spark ignited, verify that the spark plugs and spark plug wires are resistive type, and the ignition is properly grounded.
ix. Even though the iGUARD passes the EC requirement for immunity to radiated noise, beyond a certain point - *very* strong field strengths - EMI/RFI can still cause problems. Turn off radio gear and try running again.
x. Check that the governor is correctly set for this application. Sometimes a governor with too much overall gain, (or some other aspect of the governors PID loop set wrong) will experience overshoot at startup or from a block load event and the overspeed bubble timer will expire before the RPM drops back below the setpoint
f. Overcrank
i. Check that the fuel solenoid/governor is connected to the correct relay (default is K3)
ii. Check that the fuel control relay is connected properly
iii. Check that there is +V battery to the common of the fuel relay
iv. Check that the fuel solenoid/governor is actually receiving power during cranking
v. Verify that there is fuel in the fuel system
g. Low fuel level
i. Check the shutdown history to see the value of the parameter at shutdown. Verify that this is the correct value for your application
ii. Check the Warning/Status screen for currently active errors and warnings. Take the necessary steps to correct the warnings and/or errors
iii. Sometimes, a loose wire can cause a shutdown that will masquerade as a totally different problem. Check that the wires to the senders are connected securely.
iv. Check that the return wire from the sender actually comes back to the iGUARD, and is not in fact grounded to the frame.
h. Low oil level - Sometimes, a loose wire can cause a shutdown that will masquerade as a totally different problem.
i. Check that the wires to the oil level device are connected securely.
ii. Check that the signal wire from the low oil level device to the controller is intact - no nicks, cuts, or crushing of the cable.
i. Low coolant level
i. Check that the wires to the coolant level device are connected securely.
ii. Check that the signal wire from the low coolant level device to the controller is intact - no nicks, cuts, or crushing of the cable.
8. Controller has shutdown, and won't restart - The iGUARD must be reset:
a. Press the "ACK ALARM" key three times - The display will indicate that you must press the acknowledge key some number of times to cause a reset.
b. Cycle power to the controller (OFF, wait a few seconds and then back ON)
9. Multiple senders for the same parameter - If your system has a split cooling rail, or split lubrication rail, you could be in a position where to properly monitor and protect the engine the system requires a left & right side coolant temperature or oil pressure. The iGUARD facilitates this by allowing any label to be assigned to multiple input channels. The first one (based on input channel number) is the primary, the second is the Aux 1, the third is the AUX 2 etc... If a coolant temperature sender is attached to Analog input 1, and another coolant temperature is attached to analog input number 2, the display screens will say "Coolant temp for analog 1 values and "Aux 1 temp" for analog channel 2 values. However, they both use the same setpoints for warnings and shutdowns. So, even if sender 1 is operating properly and displaying a value that is perfectly acceptable, if aux temp 1 is reading outside of the coolant temperature setpoints, there will still be warnings and shutdowns displayed as "Coolant Temp. WARNING' This can be avoided by clicking on the "disable multiple senders" on the iGCON setup program, or by reprogramming or disabling the unneeded analog input
10. Engine parameters are consistently wrong - The primary cause of the engine parameters reading wrong ("off" or in error) is usually something to do with the senders. Check the following:
a. Is the correct manufacturer of sender selected?
b. Is the correct model of sender selected? (VDO in particular has multiple resistance ranges and reverse operating modes)
c. Is the sender a two wire type? - Check to make sure that BOTH wires are brought back to the controller for best accuracy and reliability. Murphy recommends two wire senders in all cases, because they eliminate the vast majority of problems associated with grounding the sender through the engine block, voltage differentials between grounds, pipe sealing compound, Teflon® tape, ground plane noise etc.
d. Is the sender a one wire type? Make certain that the sender body is getting a good ground to the engine block. (Murphy recommends two wire senders in all cases, because they eliminate the vast majority of problems associated with grounding the sender through the engine block. Pipe sealing compound and Teflon® tape used to prevent leaks can cause the sender to NOT ground properly and then read inaccurately. The indications may also change with temperature, vibration, humidity and is very common with one wire senders)
e. Is the correct channel selected? In other words - Is the oil pressure sender channel programmed for oil pressure sender and not swapped with the engine temperature sender?
f. Is the sender functioning properly? (Does the reading make sense?) - Check this with an Ohmmeter and make sure that the sender isn't stuck, open, shorted, or damaged in some fashion
g. No luck? Contact Murphy (918) 317-4100 and ask for Technical Services
11. Engine parameters are erratic - Much like reading wrong (above), engine parameters that read erratic typically have to do with the sender.
a. Is the correct manufacturer of sender selected? The various manufacturers curves can make for big changes in display for small changes in the variable.
b. Is the correct model of sender selected? (VDO in particular has multiple resistance ranges and reverse operating modes)
c. Check that the wiring is tight and that any crimps or connections are sound, particularly if the erratic reading only happens while running (vibration causing connection problems)
d. Verify that the wiring is not crushed, partially cut through, and that the insulation is not cut through or missing.
e. Is the sender functioning properly? (Does the reading make sense?) - Check this with an Ohmmeter and make sure that the sender isn't stuck, open, shorted, or damaged in some fashion
f. No luck? Contact Murphy (918) 317-4100 and ask for Technical Services
12. Problems with Run/Idle mode - If your application uses the RUN/IDLE mode input control and you are having problems with it such as:
a. Shutting down on undervoltage/under frequency while in IDLE setting
b. NOT shutting down on undervoltage/under frequency while in RUN setting
c. NOT going to IDLE speed
d. NOT going to run speed
i. A digital input has been programmed to the "IDLE Mode Selection"
ii. A relay output has been programmed to "RUN/IDLE"
iii. The switch labeled RUN/IDLE should be set to the IDLE position
iv. On the iGUARD, scroll BACK (or NEXT) until the STATUS/ALARM screen is displayed.
v. If one line does not say "Idle bypass", then flip the run/idle switch.
vi. If it still does not say "Idle bypass", then either the switch is not wired properly, or the input is not programmed to "idle mode selection".
vii. This can be verified by entering a password that will allow access to the level 3 (or higher) parameters. (Default is PAS3 - Check your documentation!), and then navigating to the Operating Parameters Screen. Once there, use the UP/Down arrows to navigate to the "I/O TEST" menu item, and press enter.
(1) Scroll through the digital inputs until you see one labeled "Idle mode selection". Toggle the switch and verify that the input shows "0" or "1" as the switch is toggled back and forth.
(2) If the switch state does not change then there is a wiring error between the switch and the controller.
viii. If the display does say idle bypass, then we need to check the relay:
(1) If you are in a low ambient noise environment where you can hear the relays click as they change states, toggle the switch and listen for the relay to click as it changes.
(2) If there is a high noise environment, you will have to use either an Ohmmeter or a volt meter to verify that the relay is following the switch.
ix. If you can't confirm that the relay is operating, go to the RELAY screen in the programming mode. (See step 7A above)
x. Step through the relay settings and verify that one relay is programmed for "RUN/IDLE mode"
xi. Verify that there is a wire from the relay programmed for Run/Idle to the governor.
xii. Verify that the wire from the governor is connected to the appropriate terminal (Normally Open/Normally Closed) of the relay programmed for RUN/IDLE
xiii. Verify that there is a wire from the COMMON of the RUN/IDLE relay to either +V battery or Ground - As appropriate for YOUR governor! - In general, the common of the relay should be tied to a +V battery to actuate the run/idle mode, but not all governors are alike. Check the documentation on your governor to find out which setting is correct for your governor.
xiv. Start the set with the RUN/IDLE switch set to IDLE
xv. If the set immediately goes to run speed:
(1) Stop the set
(2) Change the wire from the governor to the relay to the other terminal (NO if it was NC, NC if it was NO)
xvi. If the set stays at idle, then toggle the RUN/IDLE switch. The set should go to rated speed. If the set does not, then consult the governor data and verify that this exact governor will support RUN/IDLE operation in this specific application.
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