# Wire size and fuse advice?



## Jan (Oct 5, 2009)

Tyn245GL said:


> - peak motor power 75 kW


Sorry Tyn245GL, to get immediately off topic, but where did you get this figure from? Metricmind says 40 nominal, 48 peak for the 330. You're way ahead of me, so I do not have a experienced answer to your questions. I can only say, you should not accellerate much at the cut off voltage. You better look for a safe place to park.


----------



## Tyn245GL (Oct 12, 2009)

Jan, as I understood it from MetricMind: the 330's peak power depends on the pack voltage. At 240 Volts the peak power is 40kW. At 360 Volts the peak is approx. 71kW. What voltage is your pack?


----------



## Jan (Oct 5, 2009)

Tyn245GL said:


> Jan, as I understood it from MetricMind: the 330's peak power depends on the pack voltage. At 240 Volts the peak power is 40kW. At 360 Volts the peak is approx. 71kW. What voltage is your pack?


Ah. I haven't bought a drive system yet. Still have a couple of months to look further. But there is not much else. I'm thinking of a little higher voltage pack than yours. The max possible for the tim600 so to say.


----------



## Tyn245GL (Oct 12, 2009)

Jan said:


> Ah. I haven't bought a drive system yet. Still have a couple of months to look further. But there is not much else. I'm thinking of a little higher voltage pack than yours. The max possible for the tim600 so to say.


The TIM600 peak power is 100kW, max. input voltage is 400 Volts, max. battery current is 225A. So you can make your calculations!


----------



## Jan (Oct 5, 2009)

Tyn245GL said:


> The TIM600 peak power is 100kW, max. input voltage is 400 Volts, max. battery current is 225A. So you can make your calculations!


Hi Tyn245GL,

I wish I could, but electric motor performance is still a mistery to me. 

225A at 400V is according to my calculations 90, not 100kW. And I don't think the inverter is the only one that dictates the peak power of the motor. Because this would suggest that every MES-DEA motor is capable of 90kW peak. Cooled enough. Can't believe that.


----------



## Matthijs (Jun 19, 2009)

Tyn245GL said:


> The TIM600 peak power is 100kW, max. input voltage is 400 Volts, max. battery current is 225A. So you can make your calculations!


I may be wrong here but according to this site the Tim400 does 80-400VDC, 186Amps nom., 280 Arms max. But the Tim600 does 80-400VDC, 236Amps nom., 400 Arms max. So 400A. So in theory it could do 160kW peak. Maybe invest in an over engineered water pump and you can keep things cool and get nice performance.

Edit: In the tech specs they say 350A, well still not bad but information is scarce or incorrect on these components.


----------



## CroDriver (Jan 8, 2009)

Don't forget the voltage sag in your calculations.

TS or SE cells will sag very quickly below 2,8V


----------



## Matthijs (Jun 19, 2009)

CroDriver said:


> Don't forget the voltage sag in your calculations.
> 
> TS or SE cells will sag very quickly below 2,8V


That's why I said in theory.  But if the controller/inverter can take it with proper cooling and you have batteries that will give you power this will be a great system. With TS or SE batteries it will be tough to reach the limit of the Tim600 I think.


----------



## Tesseract (Sep 27, 2008)

Tyn245GL said:


> ....
> First question: Am I right, is 50mm2 ( AWG 1/0 ) a reasonable wire size? Or would 35mm2 ( AWG 2 ) be enough?
> 
> The 50mm2 ( AWG 1/0 ) cable I am thinking of has a loading capacity of 285 Amps. The 35 mm2 ( AWG 2 ) alternative has a loading capacity of 225 Amps.
> ...


Asking how much current a wire can carry is a lot like asking how long string is... you can't really answer the question! It all depends on allowable temperature rise, the difference between peak and nominal current (along with time scale), etc. A useful site for selecting wire based on temperature rise is: UK Metric Wire Chart

I don't like to see "chassis wiring" ever exceed 80C. If a peak current persists for more than 5 seconds in this size range (20-100mm²) then I weight it with the average current draw. 

Given what you have posted, then, either 35mm² or 50mm² wire will work fine, but I'd give the nod towards 35mm² since the peak power demanded from the motor controller, averaged over time, is less than 50kW.

The fuse in this sort of application is sized to blow before the wiring melts through its insulation. 300A is a bit large because the typical fuses we use will tolerate a 2x overrcurrent for 1 minute. I would choose a 150A or 200A fuse instead. 

But doesn't the manual for the TIM-600 give you any suggestions about this???


----------



## Matthijs (Jun 19, 2009)

Tesseract said:


> ...peak rating of the motor controller is less than 50kW.


How can this be? Can you explain this to me? Thanks.


----------



## Tesseract (Sep 27, 2008)

Matthijs said:


> How can this be? Can you explain this to me? Thanks.


I explained it already in the post, but I edited the sentence in question to make it a little more clear. Essentially, I am "integrating" the current draw over time to determine the wire size.


----------



## Tyn245GL (Oct 12, 2009)

Tesseract said:


> The fuse in this sort of application is sized to blow before the wiring melts through its insulation. 300A is a bit large because the typical fuses we use will tolerate a 2x overrcurrent for 1 minute. I would choose a 150A or 200A fuse instead.


I want to use the Ferraz Shawmut A50QS fuse. Does this type also tolerate a 2x overcurrent for 1 minute? If yes then I'll select the A50QS200 (200A) version.



Tesseract said:


> But doesn't the manual for the TIM-600 give you any suggestions about this???


Unfortunately the TIM-600 manual does not provide wire or fuse sizing advice for the high voltage circuit.


----------



## Tyn245GL (Oct 12, 2009)

Matthijs said:


> I may be wrong here but according to this site the Tim400 does 80-400VDC, 186Amps nom., 280 Arms max. But the Tim600 does 80-400VDC, 236Amps nom., 400 Arms max. So 400A. So in theory it could do 160kW peak. Edit: In the tech specs they say 350A, well still not bad but information is scarce or incorrect on these components.


Remember this is an AC system. Battery DC current at the inverter input side does not equal the AC RMS at the motor side. The information I have from Metricmind is that the TIM-600 allows a maximum of 225 Amps battery current, and it has a peak power of 100 kW, with a max. output current of 350 Amps RMS (my manual says 400 Amps RMS...). Anyways, with my 340 Volt system the peak motor power I will be able to achieve will be approx. 71 kW. Lower when voltage sags occur.



Matthijs said:


> Maybe invest in an over engineered water pump and you can keep things cool and get nice performance.


The TIM-600 requires a 10 litres/min. minimum water pump. Don't know about the litres/min. requirements for the motor though. The pump I have will do 15 litres so hope that will be fine. I will not use the Volvo stock radiator (that place is taken by the front part of the front battery box), instead we will mount a smaller radiator below the original location of the radiator, just behind the front spoiler. Still need to decide which size I'd need for that though.


----------



## Tyn245GL (Oct 12, 2009)

One more question: which Anderson SB connector will I need to use, the SB350 (350 Amp model) or the SB175 (175 Amp model).

- max. battery current to inverter 225A
- water heater and DC DC converter 5kW in total will use max. 25A (during voltage sags of pack)

Total during peaks: 250 A

This is the reason why I think I need the SB350. Because I expect the SB175 will melt (or at least get damaged) during the peaks. Am I right?


----------



## Matthijs (Jun 19, 2009)

Tyn245GL said:


> Remember this is an AC system. Battery DC current at the inverter input side does not equal the AC RMS at the motor side. The information I have from Metricmind is that the TIM-600 allows a maximum of 225 Amps battery current, and it has a peak power of 100 kW, with a max. output current of 350 Amps RMS (my manual says 400 Amps RMS...). Anyways, with my 340 Volt system the peak motor power I will be able to achieve will be approx. 71 kW. Lower when voltage sags occur.
> 
> 
> 
> The TIM-600 requires a 10 litres/min. minimum water pump. Don't know about the litres/min. requirements for the motor though. The pump I have will do 15 litres so hope that will be fine. I will not use the Volvo stock radiator (that place is taken by the front part of the front battery box), instead we will mount a smaller radiator below the original location of the radiator, just behind the front spoiler. Still need to decide which size I'd need for that though.


Thank you for the explanation. With this setup even your SE 130Ah batteries will be taking it slow and last a long time because the amp draw will be low. Maybe you could go with a motorcycle type radiator and place it in the air stream? But I am sure you will come up with a very nice solution.


----------

