Re: D1D40 SSR's burning out?? [TANKS]

[Grant Mahalek <gmahalek-at-shaw.ca>]

Hey Ted,

Thanks for the input Ted. I do not have any "protect diodes" installed in 
the circuit.  Are you referring to the "Transient Protection" using fast 
recovery diodes with PIV rated greater than the supply voltage as 
illustrated/described on the www.crydom.com website.  Can you suggest what 
type and size of diode to use and how/where to install these diodes.

I'am assuming when you say "dissipation/max draw issue" you mean the motor/s 
are drawing in excess of 40 amps which may be burning out the D1D40 SSR's. 
The motors are only rated at 24vdc, 15.4 amps. I've taken the drive system 
apart....without the tracks or motor connected the gear reduction runs 
freely. In the field tests where the SSR's burned out I was using boat 
roller drive wheels....this did'nt work.....the drive wheels slipped even 
when I had the tracks so tight the 1/2" drive-shafts were bending under the 
load.

Could you please explain what you mean by "dissipation.....issue"? Any 
suggestions how this problem could be corrected?

Oh, one last thing, I was talking with an Electronics Technician yesterday 
in the LHS, he feels there may be a problem with max current draw and 
suggested installing resistors to limit the current flowing to the motors. 
What do you think? Don't know what type or size or exactly where/how to 
install.  Do you have any suggestions?

Don't hesitate to provide technical answers as my buddy Mark Townsend, a 
skilled electronics hobbyist is helping me out.

I'am building new drive wheels today using plywood discs and rubber bungee 
cord ie.-obviously a more successful design). I will be measuring the no 
load and full load(ie.-transmission and tracks installed) current on the 
bench today or tomorrow.

Thanks again, any ideas are appreciated!


Grant "thank goodnes for people more knowledgeable than me" Mahalek


----- Original Message ----- 
From: "flier" <FLIER-at-sbcglobal.net>
To: <tanks-at-rctankcombat.com>
Sent: Thursday, November 03, 2005 8:44 AM
Subject: Re: D1D40 SSR's burning out?? [TANKS]


> Hey Grant, it's Ted Callahan.
>
> If your max current is significantly below 40A, then the prob may be back 
> EMF where the protect diodes come in although I'm skeptical.  I think you 
> may have a dissipation/max draw issue.
>
> Regards,
> Ted
>
> --- Original Message ---
> From: Grant Mahalek <gmahalek-at-shaw.ca>
> To: tanks-at-rctankcombat.com
> Subject: Re: D1D40 SSR's burning out?? [TANKS]
>
>>Flier,
>>
>>Thanks for the suggestion.  I will be measuring the max current draw 
>>today.
>>Oh by the way, what's your name....I'd like to address you by your name.
>>
>>Grant "I'am learning every day" Mahalek
>>
>>
>>----- Original Message ----- 
>>From: "flier" <FLIER-at-sbcglobal.net>
>>To: <tanks-at-rctankcombat.com>; <tanks-at-rctankcombat.com>
>>Sent: Wednesday, November 02, 2005 7:15 AM
>>Subject: Re: D1D40 SSR's burning out?? [TANKS]
>>
>>
>>> Grant,
>>>
>>> Have you measured your max current draw?
>>>
>>>
>>> --- Original Message ---
>>> From: Grant Mahalek <gmahalek-at-shaw.ca>
>>> To: tanks-at-rctankcombat.com
>>> Subject: Re: D1D40 SSR's burning out?? [TANKS]
>>>
>>>>Hi Norm,
>>>>
>>>>In Test #1 the right SSR got very hot.
>>>>
>>>>I forgot to check the SSR temperatures in Test#2.
>>>>
>>>>Grant
>>>>  ----- Original Message -----=20
>>>>  From: Norman Wieser=20
>>>>  To: tanks-at-rctankcombat.com=20
>>>>  Sent: Tuesday, November 01, 2005 9:08 PM
>>>>  Subject: Re: D1D40 SSR's burning out?? [TANKS]
>>>>
>>>>
>>>>  Hi Grant
>>>>
>>>>   Did the SSR's get very Hot ?
>>>>
>>>>  Norm
>>>>    ----- Original Message -----=20
>>>>    From: Grant Mahalek=20
>>>>    To: tanks-at-rctankcombat.com=20
>>>>    Sent: Tuesday, November 01, 2005 6:27 PM
>>>>    Subject: Fw: D1D40 SSR's burning out?? [TANKS]
>>>>
>>>>
>>>>    Hi there,
>>>>
>>>>    I've run into a bit of a problem in the
>>> construction of my Hetzer.  =
>>>>I've burned out three Crydom SSR's with my Anvilus
>>> proportional motor =
>>>>controller.  I've sent off an email to
>>> www.crydom.com today in hopes of =
>>>>getting some suggestions.  The Crydom website
>>> mentions something called =
>>>>"Transient Protection" and protection of the SSR's
>>> using fast recovery =
>>>>type diodes with PIV rated greater than supply =
>>>>voltage(....cool....unfortunately I don't completely
>>> understand this). =
>>>>Has anyone out there
>>>>
>>>>    In the "Tri-Pact News Service" article
>>> entitled "R/C Combat Vehicles =
>>>>Speed Controls" under the section "Other Issues"
>>> various devices are =
>>>>recommended to limit power surges and radio
>>> interference.  After a small =
>>>>fix(installation of a CMOS NAND 4011 Gate) into the
>>> steering and =
>>>>throttle servo leads, radio interference is no
>>> longer a problem.
>>>>
>>>>    However, burning out these SSR's is becoming a
>>> bit of a =
>>>>pain....xxo!!/?##.
>>>>
>>>>    Can anyone out there offer suggestions, detailed
>>> or otherwise on how =
>>>>to overcome this obstacle?  Any suggestions would be
>>> much appreciated.
>>>>
>>>>    Oh, by the way, the rubber boat roller drive
>>> wheels did not work, =
>>>>the rubber was too hard and the drive wheels slipped
>>> in the tracks.  =
>>>>I'am going to use the "tried and true" TTS rubber
>>> bungee cord wrapped =
>>>>plywood drive wheels.  And for those of you
>>> wondering about what =
>>>>thickness of drive-shaft to use, I support Steve
>>> Tyng's suggestion to =
>>>>use a hardened steel shaft > 1/2 inch.  I've already
>>> bent both my 1/2 =
>>>>inch drive shafts in the minimal testing I've done
>>> so far.
>>>>
>>>>    Supper call....thanks for any help you guys can
>>> offer.
>>>>
>>>>
>>>>    Grant P. Mahalek
>>>>
>>>>    ----- Original Message -----=20
>>>>    From: Grant Mahalek=20
>>>>    To: support-at-crydom.com=20
>>>>    Sent: Tuesday, November 01, 2005 7:33 AM
>>>>    Subject: D1D40 SSR's burning out??
>>>>
>>>>
>>>>    Hello there,
>>>>
>>>>
>>>>    I'am a hobbyist using a pair of Crydom D1D40
>>> SSR's with a motor =
>>>>controller to provide proportional speed control for
>>> a custom built 1:6 =
>>>>scale radio control combat tank. The motor controller
>>> (Anvilus RC Relay =
>>>>SSR Motor Controller; Board h_050412, Manual 050425)
>>> is described in =
>>>>detail at www.anvilus.com . The motor and control
>>> system is wired =
>>>>according to figure 3, page 5 of the manual.  I'am
>>> using a pair of new =
>>>>electric scooter motors(MY1016) from
>>> www.unitemotor.com operated at =
>>>>24Vdc. Motor specifications: 24Vdc, 2750 rpm,
>>> 15.4amps, 280watts. There =
>>>>is a 40 amp automotive fuse installed in-line on the
>>> each motor power =
>>>>lead.  No other circuit protection is provided.
>>>>
>>>>    I have burned out three(3) Crydom D1D40 SSR's
>>> thus far.  This is =
>>>>getting a little expensive for a hobby......
>>>>
>>>>    Can you help?
>>>>
>>>>    Circumstances of failures:
>>>>
>>>>    1.)Test #1; left SSR failed; left SSR -1
>>> terminal wires became loose =
>>>>during tank test run. Up to this time(20 minutes of
>>> run time), the =
>>>>electronics and drive system were operating with
>>> full mixing and =
>>>>proportional speed control.  Right drive motor and
>>> right SSR became very =
>>>>hot.
>>>>
>>>>    2.)Test #2; right SSR failed after about 20
>>> minutes of fully =
>>>>proportional run-time. No apparent loose electrical
>>> connections. No =
>>>>apparent mechanical binding in drive-train. Right
>>> drive motor became =
>>>>very hot.
>>>>
>>>>    Apparently, there are twenty to thirty RC combat
>>> tanks using the =
>>>>same electronics(with Crydom SSR's) and drive
>>> systems with almost =
>>>>identical components with no problems.
>>>>
>>>>    Do you have any suggestions regarding the
>>> inclusion of circuits or =
>>>>components to protect the SSR's from being burned
>>> out.  Could you please =
>>>>be very specific with any suggestions regarding
>>> protective circuits or =
>>>>components(ie.-component/circuit installation into
>>> motor control wiring =
>>>>and type and specific sizes of and sizes of any
>>> components).=20
>>>>
>>>>
>>>>    Thank you,
>>>>
>>>>
>>>>    Grant P. Mahalek
>>>>    gmahalek-at-shaw.ca
>>>>    403-948-6443(res)
>>>>    403-880-2070(bus, cell)
>>>>
>>>>
>>>>
>>>>
>>>>
>>>>
>>>
>>>
>>>
>>
>>
>
>
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