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Z12 questions

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Bob Barrow

Joined: 11 Jan 2006
Posts: 29

Posted: Tue Jun 09, 2009 5:06 am Post subject: Z12 questions

I already have a B&C 40 amp alternator and a B&C SD20 aux alternator installed on my Lycoming. I also have 2 B&C  LR3 regulators. Now I'm contemplating swapping one of the LR3 regs for a SB-1 and using architecture Z12. I'm planning on an IFR ship for long distance international flights.

  

 These are my questions:

  

 1. Is the battery contactor on Z12 a single point of failure that will take out both of my alternators and leave me with only battery power. If so is there a mod to Z12 that gets around this.

  

 2. Under certain extreme power use configurations I may marginally exceed the capacity of the 40 amp main alternator. If the capacity of the 40 amp alternator is exceeded and the bus voltage sags will the 20 amp aux alternator switch on automatically (when regulated by the SB-1 regulator) and run concurrently with the 40 amp main alternator to effectively provide 60 amps of useable current. 

  

 Regards Bob Barrow

 RV7A

Click Here View photos of singles in your area  [quote][b]

rckol

Joined: 14 Nov 2008
Posts: 36

Posted: Tue Jun 09, 2009 7:11 am Post subject: Re: Z12 questions

I would consider keeping the LR3 and use Z-14.  It would address both of your concerns.  You would need another battery though.

_________________
rck

nuckolls.bob(at)aeroelect
Guest

Posted: Tue Jun 09, 2009 12:19 pm Post subject: Z12 questions

At 10:11 AM 6/9/2009, you wrote:

 	  Quote: 	
		  



I would consider keeping the LR3 and use Z-14.  It would address 

both of your concerns.  You would need another battery though.



--------

rck


	




    Good answer. Z12 is a dual alternator enhancement of

    Z12 that emulates the SD20 standby alternator offered

    as STC on LOTS of TC aircraft.



    I'll suggest that Z-13/8 is the elegant solution for

    cost/weight/performance/reliability/simplicity. If

    you're going to hang an SD20 on a fresh design, then

    Z-14 is the better if not a bit heavier choice.



    You can go to the smallest of engine cranking

    batteries because of Z-14's ability to parallel them

    during cranking.



    Alternatively, battery contactor failure is pretty

    rare . . . and you have the e-bus alternate feed to

    back it up. You could consider a premium low-power

    contactor and probably be just fine with Z-12 and

    and SD-20/LR3 combination.

        Bob . . .



         ---------------------------------------

        ( . . .  a long habit of not thinking   )

        ( a thing wrong, gives it a superficial )

        ( appearance of being right . . .       )

        (                                       )

        (                  -Thomas Paine 1776-  )

         ---------------------------------------

nuckolls.bob(at)aeroelect
Guest

Posted: Tue Jun 09, 2009 12:21 pm Post subject: Z12 questions

At 08:00 AM 6/9/2009, you wrote:

  	  Quote: 	
		   I already have a B&C 40 amp alternator and a B&C SD20 aux alternator installed on my Lycoming. I also have 2 B&C  LR3 regulators. Now I'm contemplating swapping one of the LR3 regs for a SB-1 and using architecture Z12. I'm planning on an IFR ship for long distance international flights.

  

 These are my questions:

  

 1. Is the battery contactor on Z12 a single point of failure that will take out both of my alternators and leave me with only battery power. If so is there a mod to Z12 that gets around this.

  

 2. Under certain extreme power use configurations I may marginally exceed the capacity of the 40 amp main alternator. If the capacity of the 40 amp alternator is exceeded and the bus voltage sags will the 20 amp aux alternator switch on automatically (when regulated by the SB-1 regulator) and run concurrently with the 40 amp main alternator to effectively provide 60 amps of useable current. 	


   Yes, you can run both alternators together but

   getting them to share proportionately is difficult

   without special paralleling regulators.



   What situation demands more than 40A?



   Alternatively, consider Z-14 and split the

   loads between the two alternators.



 

        Bob . . .



         ---------------------------------------

        ( . . .  a long habit of not thinking   )

        ( a thing wrong, gives it a superficial )

        ( appearance of being right . . .       )

        (                                       )

        (                  -Thomas Paine 1776-  )

         ---------------------------------------



     [quote][b]

Bob Barrow

Joined: 11 Jan 2006
Posts: 29

Posted: Wed Jun 10, 2009 4:24 am Post subject: Z12 questions

 Date: Tue C 9 Jun 2009 15:20:29 -0500

To: aeroelectric-list(at)matronics.com

From: nuckolls.bob(at)aeroelectric.com

Subject: Re: AeroElectric-List: Z12 questions

 > Yes C you can run both alternators together but

  >getting them to share proportionately is difficult

  >without special paralleling regulators.

 Bob C what exactly happens with architecture Z12 (with specifically one LR3 and one SB-1 regulator) if you keep turning on major loads (pitot C landing lights C etc) until the primary L40 alternator can no longer cope and the voltage sags. Will the SD20 come on and run concurrently. I presume it will... until some of the loads are shed..but from  your comment above it may not be a happy event over time. Can you please elaborate on this. Is it possible that one or both of the alternators (or the regulators) could be damaged if both alternators are running concurrently in Z12.

 I'm trying to work out whether with Z12 I need to ensure that my primary alternator is never pushed beyond its capacity (ie swap the L40 for an L60).

 Regards Bob Barrow

Click here to find out more POP access for Hotmail is here!  [quote][b]

nuckolls.bob(at)aeroelect
Guest

Posted: Wed Jun 10, 2009 5:10 am Post subject: Z12 questions

At 07:22 AM 6/10/2009, you wrote:

  	  Quote: 	

 Date: Tue, 9 Jun 2009 15:20:29 -0500

 To: aeroelectric-list(at)matronics.com

 From: nuckolls.bob(at)aeroelectric.com

 Subject: Re: Z12 questions

  > Yes, you can run both alternators together but

   >getting them to share proportionately is difficult

   >without special paralleling regulators.

  Bob, what exactly happens with architecture Z12 (with specifically one LR3 and one SB-1 regulator) if you keep turning on major loads (pitot, landing lights, etc) until the primary L40 alternator can no longer cope and the voltage sags. Will the SD20 come on and run concurrently. I presume it will... until some of the loads are shed..but from  your comment above it may not be a happy event over time. Can you please elaborate on this. Is it possible that one or both of the alternators (or the regulators) could be damaged if both alternators are running concurrently in Z12.

 I'm trying to work out whether with Z12 I need to ensure that my primary alternator is never pushed beyond its capacity (ie swap the L40 for an L60). 	

    The "sharing" scenario you described is correct

    when the SD-20 is regulated by the SB-1 and the

    aux alternator setpoint is about 1 volt lower than

    the main alternator.

    As long as your main alternator is adequately

    cooled, there is no risk of damage to the main

    alternator. I was curious as to what kind of loads

    you are anticipating that would require over

    30A of continuous engine driven power.

    For example, you wouldn't have any exterior lights

    on along with pitot heat. 

        Bob . . .

         ---------------------------------------

        ( . . .  a long habit of not thinking   )

        ( a thing wrong, gives it a superficial )

        ( appearance of being right . . .       )

        (                                       )

        (                  -Thomas Paine 1776-  )

         ---------------------------------------

     [quote][b]

Jim Berry

Joined: 10 Jan 2006
Posts: 237
Location: Denver

Posted: Wed Jun 10, 2009 8:30 am Post subject: Re: Z12 questions

Bob,



This raises a question that I know has been discussed before, but I could not find in the archives. I have a Plane Power 60A and a SD20. What are the pros and cons of using two LR3 's versus one LR3 and one SB-1? Thanks.



Jim Berry

RV10

Bob Barrow

Joined: 11 Jan 2006
Posts: 29

Posted: Sun Jun 14, 2009 5:44 am Post subject: Z12 questions

As others have suggested C it does seem like Z14 is my best option as I have the L40 and SD20 already installed and I have 2 off LR3 regulators. Too much trouble and expense to go sending back things to B&C for exchange now from Australia.

 So I have purchased a second Odyssey AGM battery C in this case a PC310 which is 7AH and weighs very little (2.7kg). 

 Do you foresee of any problems with running the SD20 with the PC310 on the secondary bus.

 Cheers Bob 

  Date: Wed C 10 Jun 2009 08:07:28 -0500

To: aeroelectric-list(at)matronics.com

From: nuckolls.bob(at)aeroelectric.com

Subject: RE: AeroElectric-List: Z12 questions

At 07:22 AM 6/10/2009 C you wrote:

  	  Quote: 	

Date: Tue C 9 Jun 2009 15:20:29 -0500

To: aeroelectric-list(at)matronics.com

From: nuckolls.bob(at)aeroelectric.com

Subject: Re: AeroElectric-List: Z12 questions

 > Yes C you can run both alternators together but

  >getting them to share proportionately is difficult

  >without special paralleling regulators.

 Bob C what exactly happens with architecture Z12 (with specifically one LR3 and one SB-1 regulator) if you keep turning on major loads (pitot C landing lights C etc) until the primary L40 alternator can no longer cope and the voltage sags. Will the SD20 come on and run concurrently. I presume it will... until some of the loads are shed..but from  your comment above it may not be a happy event over time. Can you please elaborate on this. Is it possible that one or both of the alternators (or the regulators) could be damaged if both alternators are running concurrently in Z12.

I'm trying to work out whether with Z12 I need to ensure that my primary alternator is never pushed beyond its capacity (ie swap the L40 for an L60). 	

   The "sharing" scenario you described is correct

   when the SD-20 is regulated by the SB-1 and the

   aux alternator setpoint is about 1 volt lower than

   the main alternator.

   As long as your main alternator is adequately

   cooled C there is no risk of damage to the main

   alternator. I was curious as to what kind of loads

   you are anticipating that would require over

   30A of continuous engine driven power.

   For example C you wouldn't have any exterior lights

   on along with pitot heat. 

        Bob . . .

        ---------------------------------------

       ( . . .  a long habit of not thinking   )

       ( a thing wrong C gives it a superficial )

       ( appearance of being right . . .       )

       (                                       )

       (                  -Thomas Paine 1776-  )

        ---------------------------------------

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rckol

Joined: 14 Nov 2008
Posts: 36

Posted: Sun Jun 14, 2009 6:04 am Post subject: Re: Z12 questions

Jim,



I am not Bob, but will offer a response based on my own study.



In both the Z-12 and Z-14 architectures, your SB-20 can be connected to any and all electrical devices on the ship. In the event that you loose your big alternator, it is up to you to manage your electrical usage to keep your consumption within with your means (batteries + SB-20).  



In this scenario, the advantage of the SB-1 is that it can provide you with an indication that you are reaching the current capacity of the alternator with an indicator light.  



With the LR-3, you are going to have to monitor this with an ammeter or load meter.

_________________
rck

klehman(at)albedo.net
Guest

Posted: Sun Jun 14, 2009 11:53 am Post subject: Z12 questions

Not positive what you are asking Bob but I'm approaching 300 hours with 

a 20 amp permanent magnet alternator and an 8AH battery as the second 

part of a Z-14 system. I run the strobes and a few things off that 

system and everything else off the other battery and 40 amp ND 

alternator. The voltage starts to sag a bit if you draw much more than 

20 amps of course. The system works very well for my purposes.



Both my batteries are 8AH and they auto parallel for cranking. That way 

I can still crank the electric dependent geared engine even if a battery 

is dead and the engine has stopped windmilling.



Ken



Bob Barrow wrote:

 	  Quote: 	
		   As others have suggested, it does seem like Z14 is my best option as I 

 have the L40 and SD20 already installed and I have 2 off LR3 regulators. 

 Too much trouble and expense to go sending back things to B&C for 

 exchange now from Australia.

  

 So I have purchased a second Odyssey AGM battery, in this case a PC310 

 which is 7AH and weighs very little (2.7kg). 

  

 Do you foresee of any problems with running the SD20 with the PC310 on 

 the secondary bus.

  

 Cheers Bob

nuckolls.bob(at)aeroelect
Guest

Posted: Mon Jun 15, 2009 5:24 am Post subject: Z12 questions

At 08:29 AM 6/14/2009, you wrote:

 	  Quote: 	
		  As others have suggested, it does seem like Z14 is my best option as 

I have the L40 and SD20 already installed and I have 2 off LR3 

regulators. Too much trouble and expense to go sending back things 

to B&C for exchange now from Australia.



So I have purchased a second Odyssey AGM battery, in this case a 

PC310 which is 7AH and weighs very little (2.7kg).



Do you foresee of any problems with running the SD20 with the PC310 

on the secondary bus.



Cheers Bob


	


   No problems at all.



        Bob . . .



         ---------------------------------------

        ( . . .  a long habit of not thinking   )

        ( a thing wrong, gives it a superficial )

        ( appearance of being right . . .       )

        (                                       )

        (                  -Thomas Paine 1776-  )

         ---------------------------------------

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