SB200 and other Heathkit circuit breakers

[Kenneth Bakhaus]

To the green & gray as promised:

Here's the scoop on the CBs used in Heathkits up to about 1980. Initial
review of the inactive files finds no record of sales of these units after
1980 although there was a spares RFQ in 1984 but no confirmation that they
were actually purchased. Most business records of this type are only
retained for 7 years. Mechanical Products (by the way, I am speaking only
as ham to ham, not as a representative of MP on this issue but am very
knowledgable about these general products) produced 6 different CBs for
Heath in the 60s & 70s per the following:

Heath P/N       rating(A)       product usuage
65-15           8               SB200
65-22           50              MP-14
65-28           10              SB220
65-30           15              GD-29
65-31           3               GD-29
65-36           20              GD-29

I don't know what the GD and MP models were. Maybe the GD was "garage door"
actuators. I have a GDA-3201-1 deluxe garage door actuator (non-operational
due to broken plastic part in drive mechanism) which I would sell or part
out if there's any interest.

The SB200 8 amp unit in present question is a little special but not much
different from the standard 8 amp device produced today. The trip time
calibration for these standard thermal actuated 8 amp devices @ 200%
overload (16A) is 5.2 to 11.2 seconds (in 77? F ambient) whereas the SB200
unit was to have a 10.5 second max. trip time at this overlaod. Thermally
actuated CBs require a cooling time before they can be reset, normally of
2.5 to 30 sec. Heath wanted the max reset time limited to 20.5 sec. It is
my opinion that these small differences would be insignificant BUT CAN NOT
GUARRANTEE THERE IS NOT SOME EFFECT OF THE SLIGHTLY LONGER TRIP TIME!! The
longer possible reset time of the standard unit means, at worst, you have
to be without the linear for an extra 10 sec. following a trip out. You
must understand that these types of devices are designed to protect wire
against fire/smoke, not electronics. I would doubt that the .7 sec
difference would save the tubes or power supply.

If one wants instantaneous trip on overload, then magnetic type breakers
must be used. However, magnetics will trip from the surge on "turn on" due
to the power supply caps charging. "Dampened" magnetics fall in between the
two responses. (Always thought I should write an article for QST/CQ etc. on
various protective devices (fuses and different CB types) but never have.
Even all thermal CB devices from several manufactures are "not created
equally" and I have presented a paper on that area.) Actually, these
devices are not true CBs by UL/CSA definition anyway but rather circuit
protectors and that's a whole other story.

Back to the question at hand. Available standard P/Ns today are:

        1600-001-08000  or 1600-037-08000

Both of these have white buttons rather than red and the -037 types have
the rating stamped on the end of the button. The terminals on these are
standard .25" quick connects without the large hole that the Heath unit
had. You can either punch one in or solder directly to the terminal.
Distributors who carry these are:

RCO Sales (Cleveland area)- 1-800-654-4636
WES-GARDE(several locations) 1-800-554-8866

I have no idea what distributor pricing is.

The other CBs noted above have GREATER DIFFERENCES from standard products
and I would have to make some calculations to see what might even be close
if someone needs those. Hollar  if you have any questions regarding these
devices.

ken-K8PAO

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