WOT Poll - How often do you use wide open throttle?

[breeves002]

Good to know, thanks. So how is the contactor being damaged?

Well no one actually knows. Speculation is too much heat causing warping of the case, etc. However it could be pitting over time from poor management of when it closes/opens.

Thanks; maybe you can help me understand a bit better. I understand that there is a contact for motors and one for DCFC. What is the difference DCFC with the car powered on and with it powered off and which is better. Would two sets of contacts be closed when powered on and DCFC and only one when powered off DCFC?

When DCFC both sets of contactors are closed. The DC DC converter has to run to charge the 12v battery and run the various systems required while DCFC is going on. Doesn't matter if you have the car on or off. When not DCFC those contactors stay open all the time.

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[Shayne]

Well no one actually knows. Speculation is too much heat causing warping of the case, etc. However it could be pitting over time from poor management of when it closes/opens.


When DCFC both sets of contactors are closed. The DC DC converter has to run to charge the 12v battery and run the various systems required while DCFC is going on. Doesn't matter if you have the car on or off. When not DCFC those contactors stay open all the time.

So when the HVJB is removed the mechanic can physically see the contact has overheated and the housing is physically damaged. I will ask my guys if they was noted this next time I talk to them. My positive contact sticks open in the cold and lets the 12V die.

Thanks again the the best way to stop DCFC would be? At the station, the station app, the unlock button of the car? Which is easier on the component or it also does not matter as long as I can disconnect it?

 

[gpgrim]

And you've described the reason whey high current loads can be problematic for contactors - and the likely reason why WOT can cause issues. It's not the load while the contactor is closed - unless it is high enough to exceed the heat capacity of the system. It is rapid lifting off the WOT. Breaking the connection at high current load will cause an arc and apparently in the MME contactors can damage and or weld them together. This is why Ford thinks they can mitigate with software. If they can sense a potentially dangerous loading they can reduce the load before opening the contactor. It will be interesting to see how or if this impacts the driving experience for those who like to use WOT.

I freely admit I don't have a schematic and therefor a precise knowledge of the circuit, but I think it's reasonable to assume, based on what a contactor is, that it is not being operating during throttling.

The purpose of contactors is to act as an HV switch, or isolator, thereby protecting the low voltage control circuit from damage. For example, contactors are regularly used in industrial motors to close the circuit for a 240/480V motor that draws 10s to 100s of A, but using a low voltage (3.3-24 V) DC control circuit.

Okay, fully admitting I don't know the circuit, but understand how these devices work, and that they are not the type of deices you want switching on and off willy nilly, particularly when driving, my interpretation of why there are 4 contactors in the dual motor vehicle that Munro's gang tore down, is to isolate the 4 main electrical sub-systems attached to the HVB, namely 1-2) the two induction motors, 3) the charging system, and 4) the low voltage battery system.

Although I can't know the logic of exactly when the motor contactors are operated, I think it is safe to say once the control logic thinks you plan to drive, the circuit is made for the motors and left active until the logic thinks you are done, and then it deactivates. While closed the only thing operating the throttle does is alter the amount of current flowing to the inverters through the electrodes.

Now there is one circuit which could have willy-nilly operation, and this depends on the logic FoMoCo developed for the 12V batt circuit. Here there must be some monitoring circuitry which determines when the 12-volt batt charge circuit will be connected to the HVB for fresh electrons. This will be demand driven, i.e. running down the road with the AC blasting on a 100 degree day, vs. a 70 degree day where no AC is required. Mileage here may vary. This demand signal could be too needy, and could occur in non-op conditions, i.e. when at home sitting in the garage.

Again, all speculation, I freely admit, however, I think its more consistent with the symptoms and the modes of operation for contactors, but I'm sure their are more knowledgeable folk on this forum who could speak with direct experience on contactors that could shed even more light here.

 

[MailGuy]

Doesn't everyone just pulse-width-modulate driving? (either 0% or 100%...no inbetween)?

Spoken like a programmer ?. 10 types of people in this world, those that speak binary and those that do not.

 

[gpgrim]

Okay, fully admitting I don't know the circuit, but understand how these devices work, and that they are not the type of deices you want switching on and off willy nilly, particularly when driving, my interpretation of why there are 4 contactors in the dual motor vehicle that Munro's gang tore down, is to isolate the 4 main electrical sub-systems attached to the HVB, namely 1-2) the two induction motors, 3) the charging system, and 4) the low voltage battery system.

After thinking about this in the shower, the 4 circuits must be: 1) Drive motor(s), 2) DC Charing, 3) On-board charging, 4) Low volt Batt system.

 

[Shayne]

This demand signal could be too needy, and could occur in non-op conditions, i.e. when at home sitting in the garage.

Mine fails when parked sitting still. The positive contact does not close and the 12V dies. What would you speculate is causing that at -28C?

 

[DadzBoyz]

I still think it is strange that Ford plans to handle this with a software update without any inspection of the contactor. How will they know it is not on the verge of failing just before the update?

As far as the pole, note there is not any option for several times a week which would be between rarely and every time I drive. Also, every time my wife is not in the car should be one of the options as well.

The software update monitors the temp and flow of electricity through the contactors. They can tell if the contactors are bad or nearly bad based on their temperature and variations in the flow of electricity through them.

 

[breeves002]

So when the HVJB is removed the mechanic can physically see the contact has overheated and the housing is physically damaged. I will ask my guys if they was noted this next time I talk to them. My positive contact sticks open in the cold and lets the 12V die.

Thanks again the the best way to stop DCFC would be? At the station, the station app, the unlock button of the car? Which is easier on the component or it also does not matter as long as I can disconnect it?

They may or may not be able to tell by looking at it. Contactors don't stick open generally they get stuck closed (though it is possible). I doubt you have a contactor sticking open or you wouldn't be able to start the car sometimes and get a stop safely now when attempting to start the car. Along with contactor stuck open codes.

I freely admit I don't have a schematic and therefor a precise knowledge of the circuit, but I think it's reasonable to assume, based on what a contactor is, that it is not being operating during throttling.

The purpose of contactors is to act as an HV switch, or isolator, thereby protecting the low voltage control circuit from damage. For example, contactors are regularly used in industrial motors to close the circuit for a 240/480V motor that draws 10s to 100s of A, but using a low voltage (3.3-24 V) DC control circuit.

Okay, fully admitting I don't know the circuit, but understand how these devices work, and that they are not the type of deices you want switching on and off willy nilly, particularly when driving, my interpretation of why there are 4 contactors in the dual motor vehicle that Munro's gang tore down, is to isolate the 4 main electrical sub-systems attached to the HVB, namely 1-2) the two induction motors, 3) the charging system, and 4) the low voltage battery system.

Although I can't know the logic of exactly when the motor contactors are operated, I think it is safe to say once the control logic thinks you plan to drive, the circuit is made for the motors and left active until the logic thinks you are done, and then it deactivates. While closed the only thing operating the throttle does is alter the amount of current flowing to the inverters through the electrodes.

Now there is one circuit which could have willy-nilly operation, and this depends on the logic FoMoCo developed for the 12V batt circuit. Here there must be some monitoring circuitry which determines when the 12-volt batt charge circuit will be connected to the HVB for fresh electrons. This will be demand driven, i.e. running down the road with the AC blasting on a 100 degree day, vs. a 70 degree day where no AC is required. Mileage here may vary. This demand signal could be too needy, and could occur in non-op conditions, i.e. when at home sitting in the garage.

Again, all speculation, I freely admit, however, I think its more consistent with the symptoms and the modes of operation for contactors, but I'm sure their are more knowledgeable folk on this forum who could speak with direct experience on contactors that could shed even more light here.

After thinking about this in the shower, the 4 circuits must be: 1) Drive motor(s), 2) DC Charing, 3) On-board charging, 4) Low volt Batt system.

What you're right about: Once the car is on the contactors stay closed. They don't open until the car is turned off or the battery needs to be isolated (such as in an accident).

What you're wrong about: HV Circuits. There's exactly 2 sets of contactors (+ and - for each set) in the HVBJB. 1 set sends power to the whole car. This includes the DC DC converter, the motors, from the on board charger (AC Charger), etc. The other set is JUST for the DCFC pins on the charge connector.

 

[breeves002]

The software update monitors the temp and flow of electricity through the contactors. They can tell if the contactors are bad or nearly bad based on their temperature and variations in the flow of electricity through them.

They don't monitor contactor temperature as there are no sensors. They monitor voltage drop to measure resistance. Higher resistance = more heat generated.

 

[Chuck]

Hey, I have a year to go until I can go to traffic ticket school again. I don't need an "exhibition of speed" or "reckless driving" ticket to show up for my insurance company to see.

 

[Shayne]

They may or may not be able to tell by looking at it. Contactors don't stick open generally they get stuck closed (though it is possible). I doubt you have a contactor sticking open or you wouldn't be able to start the car sometimes and get a stop safely now when attempting to start the car. Along with contactor stuck open codes.

Once the 12V is dead I get lots of error messages and ssn is one of them but it does not go in gear and is parked. Charge the 12V back in action. Keep it on a 12V charger when cold not a problem. Works well in the summer.

============1==============
P0AA2
Raw code: 0AA2
ECU: 7EC
Status: Confirmed
OBDII: Hybrid battery positive contactor - circuit stuck open

============2==============
U0594
Raw code: C594
ECU: 7EC
Status: Confirmed
OBDII: Invalid data received from hybrid powertrain control module

Replacing the BECM may fix it? Happened to a few up here.

 

[DadzBoyz]

They don't monitor contactor temperature as there are no sensors. They monitor voltage drop to measure resistance. Higher resistance = more heat generated.

Understood.
I was aware of that, but was trying to simplify and get to the point.

 

[DadzBoyz]

Once the 12V is dead I get lots of error messages and ssn is one of them but it does not go in gear and is parked. Charge the 12V back in action. Keep it on a 12V charger when cold not a problem. Works well in the summer.

============1==============
P0AA2
Raw code: 0AA2
ECU: 7EC
Status: Confirmed
OBDII: Hybrid battery positive contactor - circuit stuck open

============2==============
U0594
Raw code: C594
ECU: 7EC
Status: Confirmed
OBDII: Invalid data received from hybrid powertrain control module

Replacing the BECM may fix it? Happened to a few up here.

Yes. This is one of the possible scenarios covered by the recall.

1. Contactors stuck closed/on. In this case, put simply, the two pieces of metal connect to send electricity to the motor(s), 12v, or other systems. The resistance is too high, the metal heats up too much, and basically the two pieces of metal weld themselves together and can no longer separate.

2. The opposite. The two pieces of metal are locked open/off and cannot connect (close/on) to allow electricity to transfer to the respective system (motor(s), 12v, ADAS, etc.). There can be a number of causes for this. One is, while closed, the metal heats up enough to damage another part of the contractor module, like a spring used to connect and disconnect the metal pieces, and the connection can no longer be made.

It appears that you are having problem 2, and the contactors cannot connect to charge the 12v battery/system.

 

[Dave-O]

Hell, my wife and I thought the go pedal was just an on/off switch for the first month. I fish tailed it turning onto an avenue with the wife In the passenger seat…she giggled and asked if it was my first time ?

 

[Shayne]

What you're wrong about: HV Circuits. There's exactly 2 sets of contactors (+ and - for each set) in the HVBJB. 1 set sends power to the whole car. This includes the DC DC converter, the motors, from the on board charger (AC Charger), etc. The other set is JUST for the DCFC pins on the charge connector.

A set is three or two? Small Pos?

It appears that you are having problem 2, and the contactors cannot connect to charge the 12v battery/system.

This happen the first week I had it -28C barely driven and just sitting there. If you remember they fixed it with software right at the beginning by the time it warmed up. Second time fall -15C 2 50KW DCFC's parked in someone's driveway over 200 miles away and 12V dead. Had a charger and got home. Replaced 12V. Sitting brand new 12V no DCFC -28C does it again. Not sure maybe damaged at the factory since it has been doing it since day one or two problems same out come? Drilling ports and having a 12V charger in the frunk is still my course of action until we see if it can get thru the third winter season and maintain itself. Not overly hyped up about it and there is a work around just need to be around a 120V and a bit of a hassle that sure I would like to see disappear. Guess we did not start too late to learn this new stuff .

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