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

["flier" <FLIER-at-sbcglobal.net>]

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)
>>>
>>>
>>>
>>>
>>>
>>>
>>
>>
>> 
>
>