Relay modification for ign sw discussion

Topic: Relay modification for ign sw discussion (Read 10431 times) previous topic - next topic

Relay modification for ign sw discussion

Reply #105 – December 27, 2012, 04:43:30 PM

Yes this is also the reason i believe the motor draws lots of current when starting. The starting current was app 14-15 Amps then leveled off to 6 Amps. I believe magnetic flux density is measured in OERSTED'S ???

Relay modification for ign sw discussion

Reply #106 – December 27, 2012, 04:49:41 PM

If you google the effect of low voltage on electric motors, you will find lots of sites saying current increases.
They treat it as common knowledge that everybody knows.
They show diagrams of readings showing it happening. But it always seems to be in an AC environment.
They don't say if it is a specific kind of motor, 1 phase, 2 phase 3 phase, inductive, synchronous, shaded pole or what have you.
And I can't find any explanation of why it happens.

Relay modification for ign sw discussion

Reply #107 – December 27, 2012, 04:56:01 PM

Oersted. Uh let me google that.
Yep unit of magnetic field strength.

Relay modification for ign sw discussion

Reply #108 – December 27, 2012, 05:19:59 PM

Today's test with my blower motor confirmed a decrease in current when the motor slowed down. I knew this before i took readings as i know many cars have an alternate battery supply normally slaved out with a relay for high fan. This was a no brainer. I for the life of me cant understand why Jay insists the current increased with a lower speed. Even in the ambulances we service the blower motors are slaved with relays for high FAN. Well just another day in Paradise!!

Relay modification for ign sw discussion

Reply #109 – December 27, 2012, 10:00:26 PM

heres a couple more charts but im not here to change the world, its your job to tell the rest of the communications industry that what they see on every outtage is a figment of thier imagination,, LOL, im just the operations guy and engineer who has to think this stuff through worse case so that the hospital down the road has power or the 911 center, or basically the whole usa can continue communicating for as long as those darn batts will last.

Relay modification for ign sw discussion

Reply #110 – December 27, 2012, 10:16:43 PM

Jay clearly you are doing something wrong. I dont know what it is but get your amprobe and check the current draws. I did this this morning and proved i was correct. With that i am tired and signing off.

Relay modification for ign sw discussion

Reply #111 – December 27, 2012, 10:21:13 PM

Quote from: TOM Renzo;405523

Jay Cars are DC, So wire can be thinner. Just a fact!!!

DC does not experience 'skin effect' that is inherent in AC (in AC, the current runs predominantly on the outside - or 'skin' - of the wire and not in the interior), meaning that for the same sized wire and same voltage, DC loses less energy per distance than AC does.

Stranded wire has more CM than solid further making it a smaller wire to carry bigger loads. Just saying!!!

yep, thats a load of horse doo doo.
seriously? wtf> if htat were the case then all our outside plants like your own CWP power co would be using dc power to your house,,LOL,

and why on earth is it such a hard concept to grasp,,
we all widely accept the fact that we "EXPECT" to see that when a battery charger is hooked to a low battery, the charger will show low battery voltage and fairly high current and then at some point the voltage will be high while the current eventually becomes low to open circuit conditoin.

the reverse happens during discharge and the reverse needs engineered into the wire size...

no tom, you cant carry carry more dc current on a smaller wire than AC. thats rediculous man even at the same voltage. that battle was over with a 100 years ago.

either way,,,

what is the answer to my question?

what is the right size ocp for the ign sw mod and why, im being serious ,, i dont just toss in a cb without knowing why im doing it and what its expectations are.
if we cant explain our design, its rather fruitless of an exercise.

Relay modification for ign sw discussion

Reply #112 – December 27, 2012, 10:24:47 PM

softtouch,
that small area you spoke to in the coup de foute represents just a couple or three minutes and is a mysterious event that occures in a lot of batteries.
you pointed out that the voltage and current were not leading to what i am saying but you are not seeing the duration of discharge or constant current discharge im speaking to.

id just suggest you call around to some people who work around batteries especially telecom or back up power and ask them....

"when the batteries go on discharge and take on the full facility load, we know the voltage drops but what happens to the current?"

Relay modification for ign sw discussion

Reply #113 – December 28, 2012, 07:36:27 AM

Jay a dead battery shows less resistance then when it is charged. Another words as the battery charges the voltage comes up as the current goes down to replenish the battery.

SO the charger is looking for battery internal resistance in a sense. Just a tip their is no current regulation in an alternator only voltage regulation. So as the alternator sees less loads on the battery and or electrical system it reduces the charge rate. LOAD is the KEY. Not current regulation. That is why they call it a VOLTAGE REGULATOR. Once again i have researched stranded V solid AC V DC and it all says the same thing. The higher the frequancy in an AC system the more of the outside of the wire is used. DC uses all the CM and their fore can have a circuit fed with thinner wire. It is not me saying this i looked it up on a SOLAR CELL plant design web site. They infatically use thinner wire with DC. So the only thing i am aware of that uses -48V is the telephone systems. Battery on the TIP and Ground on the ring. Ans 20 cycle ring generator @105 Volts !!! Are you a phone designer

Relay modification for ign sw discussion

Reply #114 – December 28, 2012, 11:22:18 AM

Quote from: TOM Renzo;405605

Are you a phone designer

I design engineer the infrustructure your using now to make this post possible and that means everything from each brick to each electron (excluding the routers, switches).
aviation electronics NEC from 86-95 active, 96-2001 reserves with sescondary EOD NEC.
Telecom industry from 95-to present with DSC communications, Alcatel, Marconi & Alpha.

Quote from: TOM Renzo;405605

Jay a dead battery shows less resistance then when it is charged. Another words as the battery charges the voltage comes up as the current goes down to replenish the battery.

now we are getting somewhere, so your saying that the battery acts differently while it is being drained. thats odd.
you are clearly saying as voltage goes up, the current goes down in a battery as its charged............ ponder that for a min,, gets you thinking doesnt it?

What size ocp needs to be placed in the ign switch mod this thread is about or is the 80A ocp you said was ok , still ok?

Relay modification for ign sw discussion

Reply #115 – December 28, 2012, 05:54:53 PM

OK here goes first what is an OCP??? Just want to be clear on this

Second Ford recalled these vehicles not for wire ampacity because the stock wiring is completely adequate feeding the Ignition switch. Ford replaced the connector or Ignition switch. As far as running a #6 cable to feed the relays that is OK but beyond the size needed. No question about that as ford did not increase the wire size as i explained in the original recall. So if i may post a wire size that is ASE certified by Automotive electrical engineers is as follows.

A 10Gauge wire in a length of 20 Feet can be used up to and including a load of 50 Amps. This is fact it is DC and the wire must be stranded. All automotive wiring is stranded for increased CM. With that i have never personally seen an ignition switch fed with heavier wire. Not 100% as i have not researched every car on this planet. So here is what we know. The recall did not include heavier wire only a heavy duty switch with better contacts to reduce heat. And a connector if the one is melted on said vehicle. So slaving out ONE circuit that i would think would be the blower circuits ETC. Once this load is off the switch it is FIXED. So be it as it may Ford did not issue a wire change as far as i know. Now feeding your relays with a #6 is fine as i said more copper better?? But in reality we are arguing about something that we all agree on. Their is to much shiznit running threw the ignition switch and that has to be addressed. If anyone wants to eliminate every load or a portion of the load that's good. But doing this accomplishes nothing once the initial high draw circuits are bypassed and slaved. I have dun many in my day and ZERO come backs using existing wiring and one 75A relay In redundant hook up for fail safe. (relay ping out while on the road and no tow truck) Thanks.

Relay modification for ign sw discussion

Reply #116 – December 28, 2012, 09:57:14 PM

yes, the automotive engineers are partially retarded, in strict violation of wiring codes because table 310.17 at 75degC allows them to use #10, but that is a ***FREE AIR*** application. once you clearly understand what the "intent" was of the use of the intentional term "free air" you will see the problem.

DC wiring does apply to the NEC per the NEC2007 on forward, stupid s didnt know shiznit about DC Power for any reasonable means until as of late the NEC2011 and they still dont know shiznit ,, these are my words and i can back em up.

so your statement to "stranded" isnt actually the better wire, pls just hear me out.

"SOL"#10 ~solid is just a single copper conductor thhn/thwn ect as you already know.

"STR" #10~ stranded is typically a bundle of a few stiff single conductors in a single insulation ,, again you know this. THese are the wires you speak of such as the types found being the yellow wires going into our ign sw.

"FX"~ flex is typically a bundle of many tiny hairs of copper , example is 350mcm STR is vastly different from 350mcm Flex being the flex has litterally thousands of copper conductors while the STR has maybe 100 "sol" conductors all within an insulation.

I endorse "Flex" because of its natual ability to exceed it the current carrying capacity of Sol or Str. The NEC is just catching up to this concept but you can find it generally in one place on our cars,,,, it resides on the battery hot cable or in a set of good quality jumper cables,, typically refered to as DLO, (diesel locomotive cable) or another would be "COPFLEX" brand by cobra wire.

No electrical wiring in a vehicle shall qualify as "FREE AIR" if in any portion of the wire travels in wire loom (considered conduit) or a bundle taped ect.. so yes, the ASE mechs are still behind the power curve.

to your point one 20Feet,, allowed for a #10wire for 50A load...............to my earlier point and proof testing the concept / application engineering......
there is another constant used for copper that is rather old school but its 10.1 kfactor instead of 11.1kfactor.

so using my previously described voltage drop formula,

10.1 x 20feet x 50A / 1vd = 10100 circular milimeters of copper required.
NEC chapter9 table 8 (conductor properties) state clearly that #10 consists of 10380 circular milimeters of copper.
This is why your ASE engineers say that #10 statisfies the 50A capacity,, they feel they are right,,, but they are wrong becaue a car is not a "FREE AIR" "application engineering"

the appropriate sized wire for this application would rightfully be #8awg ~shown in table 310.16 "in raceway" (or conduit). Again, What is the application is always the million dollar question, and since auto manuf make cars, they prob get away with things you and i would not be allowed to do.

worse of all , they being the ASE enginnering you refer to probably dont even know they are doing sub par engineerng... either that or the cost of the product would suffer greatly. Per the NEC, the only people not required to comply with the electrical wiring stardards are the Power Companies themselves.

you need to start endorsing table !! 310.16 !! and toss the generically refered to "cheap ass case scenerio" table 310.17 out the window.
If you cant explain to me why the ASE engineers bless #10 as a 50A rated conductor based on application engineering,, yes that your job to do so if your day came to court, then you might want to start asking "why" more often if not for the sake of liability. You owe your customer base an explaination and certainly each customer has his or her own intelegence level, the day you run up against someone who asks you "why" and you can only say,, "thats what the ASE engineers say is ok, sorry your car wiring caught on fire".

oh well, atleast my stuff isnt wrong.

OCP is over current protection device.

btw,, our cars do not have a relay for high speed blower ,, thought you said they did earlier, forgive me if i misunderstood you.

ok,,
so the main reason i keep dragin this out is because you had agreed and mentioned that you also confirm that you agree there is approx 20A worse case on the GY/Y wire on the ign Run circuit.
following your rule that as voltage goes down, so does current , then there is no need to go above a 30A ocp for this bypass setup as my main breaker because we would never see loads higher than that and there would never be an instance where we should worry any further than the "real load" ?? im confussed as to why you would ever consider an 80A ocp on the ign sw, it seems to me the wire would go to smoke before the breaker would trip??

In the explaination FOE presented way early in this post which i tend to agree with , you should find his point of view to be fairly impossible in that "these circuits circuits could be as high as 55A of current". im lost here, i just want to be able to explain what is being done before i do it,, thats the way i tend to roll and i know you do to.

so why is it ok to use the 80A CB? knowing the wire isnt sufficent to cause the breaker to trip first?

another question,, to your diagram,
is your N+1 redundunt relay set up applicable to my dual relay drawing such that i only need one relay instead of two and if so, i dont understand how you are doing this "RUN" and "ACCY" ckt on one relay.... i think that was what thunderchicken was saying also.

sorry so much to type here, i hate long posts but it is what it is.

Relay modification for ign sw discussion

Reply #117 – December 28, 2012, 10:17:05 PM

also,
what insulation is on the wire that the ASE engineers say this #10 can handle 50A?
i will stand corrected if you come back and say a type that is 150, 200 and 250degC rated insulation but i cant see how its possible yet.

such as type Z, fep, fepb, pfa, pfah or tfe

i have never seen the above wire types on any auto wiring except the fuel pump leads.

Relay modification for ign sw discussion

Reply #118 – December 29, 2012, 09:57:30 AM

Well it is a dead issue and i must tell you once again Ford only replaced the ignition switch in the recall. NOT THE WIRING. Weather the wiring is considered FREE AIR OR NOT. That is the way the midnighter was built and is still running today. Now please get you ammeter out and do some current readinga on blower motors. I did it already and posted my findings. As the blower motor slowed down it drew less current. By the way i know the blower motor is not slaved in the fords we are working on!!!! Why do you think the ignition switches MELT!!!! TO MUCH CURRENT. With that have a great day and i will discuss this with Jim Wilson on monday. He is a ford design engineer that i speak to quite often Thanks and have a good weekend. One more thing. I know you know your shiznit. But for some reason the car companies undersize wiring all the time according to your figures. Why i do not know. But we use the 12V tables with DC ratings for automotive grade wire and according to the tables a 20' length of #10 gauge wire can handle 50 Amps. Who am i to say they are wrong. Cheers Thanks Tom

Relay modification for ign sw discussion

Reply #119 – December 29, 2012, 10:16:08 AM

SAE wiring tables. According to ASE automotive wiring is not considered RACEWAY OR ENCLOSED BECAUSE IT IS DC!!! Dont kill me i am only the messenger

Wire Gauge Selection Table 12 Volt Circuit
AMPS    3'    5'    7'    10'    15'    20'    25'
0 to 5    18    18    18    18    18    18    18
6    18    18    18    18    18    18    18
7    18    18    18    18    18    18    18
8    18    18    18    18    18    16    16
10    18    18    18    18    16    16    16
11    18    18    18    18    16    16    14
12    18    18    18    18    16    16    14
15    18    18    18    18    14    14    12
18    18    18    16    16    14    14    12
20    18    18    16    16    14    12    10
22    18    18    16    16    12    12    10
24    18    18    16    16    12    12    10
30    18    16    16    14    10    10    10
40    18    16    14    12    10    10    8
50    16    14    12    12    10    10    8
100    12    12    10    10    6    6    4
150    10    10    8    8    4    4