Unknown Relays ITT 24A12C19A

[Computer Nerd Kev]

A while ago I bought a bunch of relays, about 20+ of which were of the same
type. Problem is that I haven't been able to find any data on them online
(and I've searched hard).

The model appears to be "24A12C19A", printed on top of the coil, and "78 08"
is above it.
Made in England by ITT.
Coil resistance is about 520R.
They work on 24V, but seem a bit sluggish.
Shape is the same as a V23154-C series relay.

Thanks for reading.

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Computer Nerd Kev <not@telling.you.invalid> wrote:

The model appears to be "24A12C19A", printed on top of the coil, and
"78 08" is above it.

The 78 08 is probably late February 1978.

I have an old NTE paper catalog ("Relays, Proximity Switches, Circuit
Breakers, and Accessories", 7th edition, copyright June 2002) that has
a cross-reference for some similar part numbers to NTE/ECG parts.

ITT? P/N NTE/ECG P/N
24A02C14C R16-11D3-12
24A02C14E R16-11D3-12P
24A02C20C R16-11D3-24
24A02C20E R16-11D3-24P

24D02C09C R16-11D5-5
24D02C14C R16-11D5-12
24D02C20C R16-11D5-24

24E02C09C R16-11D5-5
24E02C14C R16-11D5-12
24E02C14E R14-11D10-12P
24E02C20C R16-11D5-24
24E02C20E R14-11D10-24P

25A04C09C R16-17D5-5
25A04C14C R16-17D3-12
25A04C14E R16-17D5-12P
25A04C20C R16-17D3-24
25A04C20E R16-17D5-24P

25D04C14C R16-17D5-12
25D04C14E R16-17D5-12P
25D04C20C R16-17D5-24
25D04C20E R16-17D5-24P

25E04C09C R16-17D5-5
25E04C14C R16-17D5-12
25E04C14E R16-17D5-12P
25E04C20C R16-17D5-24
25E04C20E R16-17D5-24P

26A06C14C R16-23D5-12
26A06C20C R16-23D5-24

The NTE/ECG parts with 11D3, 11D5, and 11D10 are DPDT; 17D3, 17D5, and
17D10 are 4PDT; 23D5 are 6PDT. This seems to correspond to the third
and fourth numeric digits in the ITT? part number: xxx02xxxx . Yours
would be a 12PDT by this logic; does it have 36 contact pins?

The last numbers in the NTE/ECG parts are the DC coil voltages. It
looks like the last two numeric digits in the ITT? part numbers are a
code for the coil voltage, but your value of '19' isn't listed.

The NTE/ECG numbers of the form R16-xxxx-xx have a 3-48UNC screw
sticking out of the bottom, between the coil pins and the contact pins.
The R16-xxxx-xxP don't have this screw. This seems to match the C or
E suffix on the ITT? part number.

The R16 relays with D3 in the NTE/ECG part number are 3 A at 28 V DC or
120 VAC. The R16 relays with D5 in the NTE/ECG part number are 5 A
under the same conditions. The R14 relays with D10 in the NTE/ECG part
number are 10 A at 240 V AC, plus some other ratings.

I hope this helps!

Matt Roberds

 

[Computer Nerd Kev]

mroberds@att.net wrote:
> Computer Nerd Kev <not@telling.you.invalid> wrote:
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From: mroberds@att.net
Newsgroups: sci.electronics.components
Subject: Re: Unknown Relays ITT 24A12C19A
Date: Wed, 21 May 2014 06:59:44 +0000 (UTC)
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Computer Nerd Kev <not@telling.you.invalid> wrote:

The model appears to be "24A12C19A", printed on top of the coil, and
"78 08" is above it.

The 78 08 is probably late February 1978.

Ah yes, of course.

I have an old NTE paper catalog ("Relays, Proximity Switches, Circuit
Breakers, and Accessories", 7th edition, copyright June 2002) that has
a cross-reference for some similar part numbers to NTE/ECG parts.

ITT? P/N NTE/ECG P/N
24A02C14C R16-11D3-12
24A02C14E R16-11D3-12P
24A02C20C R16-11D3-24
24A02C20E R16-11D3-24P

snip

The NTE/ECG parts with 11D3, 11D5, and 11D10 are DPDT; 17D3, 17D5, and
17D10 are 4PDT; 23D5 are 6PDT. This seems to correspond to the third
and fourth numeric digits in the ITT? part number: xxx02xxxx . Yours
would be a 12PDT by this logic; does it have 36 contact pins?

Nice thinking, but they're DPDT with six pins.

The last numbers in the NTE/ECG parts are the DC coil voltages. It
looks like the last two numeric digits in the ITT? part numbers are a
code for the coil voltage, but your value of '19' isn't listed.

Though you might guess that it's between 12V and 24V. Which is strange
as they seem slow at 24V. Perhaps that's just their nature.

The NTE/ECG numbers of the form R16-xxxx-xx have a 3-48UNC screw
sticking out of the bottom, between the coil pins and the contact pins.
The R16-xxxx-xxP don't have this screw. This seems to match the C or
E suffix on the ITT? part number.

My ones have a screw there, not sure what that means with the "A" suffix
though...

The R16 relays with D3 in the NTE/ECG part number are 3 A at 28 V DC or
120 VAC. The R16 relays with D5 in the NTE/ECG part number are 5 A
under the same conditions. The R14 relays with D10 in the NTE/ECG part
number are 10 A at 240 V AC, plus some other ratings.

I hope this helps!

Thanks, it's a lot more than I've gathered from Google searches.

--
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Computer Nerd Kev <not@telling.you.invalid> wrote:
> Nice thinking, but they're DPDT with six pins.

I guess the first 1 in your part number (xxx1xxxxx) means something
else. The 2 right after that could still mean DPDT.

Though you might guess that it's between 12V and 24V. Which is strange
as they seem slow at 24V. Perhaps that's just their nature.

Have you tried the coil polarity both ways to see if it makes a
difference? How about in different orientations of the relay?

This is maybe less likely, but have you tried some small AC voltages?
You might want to do this with just one relay, and mark it, as it is
likely to get unhappy if it isn't designed for AC.

Matt Roberds

 

[Computer Nerd Kev]

mroberds@att.net wrote:

Computer Nerd Kev <not@telling.you.invalid> wrote:
Nice thinking, but they're DPDT with six pins.

I guess the first 1 in your part number (xxx1xxxxx) means something
else. The 2 right after that could still mean DPDT.

Though you might guess that it's between 12V and 24V. Which is strange
as they seem slow at 24V. Perhaps that's just their nature.

Have you tried the coil polarity both ways to see if it makes a
difference? How about in different orientations of the relay?

The relay works equally with either polarity and in all orientations.
They still switch at 12V, so I figure 24V must be close to the right
voltage if not actually it.

This is maybe less likely, but have you tried some small AC voltages?
You might want to do this with just one relay, and mark it, as it is
likely to get unhappy if it isn't designed for AC.

I'm not really motivated enough to dig through transformers/plugpacks
or rig up an amplifier for my function generator in order to test with
various AC voltages. Especially as I'm not sure how you'd be sure that
it was meant for them even if it worked to some extent. How would you
know how hot the coil is meant to get for example?

--
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#_ < |\| |< _#

 

[Baron]

Computer Nerd Kev scribbled thus:

mroberds@att.net wrote:
Computer Nerd Kev <not@telling.you.invalid> wrote:
Nice thinking, but they're DPDT with six pins.

I guess the first 1 in your part number (xxx1xxxxx) means something
else. The 2 right after that could still mean DPDT.

Though you might guess that it's between 12V and 24V. Which is
strange as they seem slow at 24V. Perhaps that's just their nature.

Have you tried the coil polarity both ways to see if it makes a
difference? How about in different orientations of the relay?

The relay works equally with either polarity and in all orientations.
They still switch at 12V, so I figure 24V must be close to the right
voltage if not actually it.

This is maybe less likely, but have you tried some small AC voltages?
You might want to do this with just one relay, and mark it, as it is
likely to get unhappy if it isn't designed for AC.

I'm not really motivated enough to dig through transformers/plugpacks
or rig up an amplifier for my function generator in order to test with
various AC voltages. Especially as I'm not sure how you'd be sure that
it was meant for them even if it worked to some extent. How would you
know how hot the coil is meant to get for example?

If you can see into the relay, assuming transparent case. You will see a
copper shading ring around the top of the pole piece on an AC relay.
This shading ring will also create the slugging effect that you
describe when using DC on an AC relay.

--
Best Regards:
Baron.

 

[Computer Nerd Kev]

Baron <baron@linuxmaniac.net> wrote:

Computer Nerd Kev scribbled thus:

mroberds@att.net wrote:
This is maybe less likely, but have you tried some small AC voltages?
You might want to do this with just one relay, and mark it, as it is
likely to get unhappy if it isn't designed for AC.

I'm not really motivated enough to dig through transformers/plugpacks
or rig up an amplifier for my function generator in order to test with
various AC voltages. Especially as I'm not sure how you'd be sure that
it was meant for them even if it worked to some extent. How would you
know how hot the coil is meant to get for example?

If you can see into the relay, assuming transparent case. You will see a
copper shading ring around the top of the pole piece on an AC relay.
This shading ring will also create the slugging effect that you
describe when using DC on an AC relay.

It has a clear case, but comparing to a known 32VDC V23154-C series relay
I can't see any difference as you describe. I don't have an AC relay of
the same design to compare though.

When I have more time, I'll try to find one of those free image hoasting
sites and put some pictures up.

--
__ __
#_ < |\| |< _#

 

[Baron]

Computer Nerd Kev scribbled thus:

Baron <baron@linuxmaniac.net> wrote:
Computer Nerd Kev scribbled thus:

mroberds@att.net wrote:
This is maybe less likely, but have you tried some small AC
voltages? You might want to do this with just one relay, and mark
it, as it is likely to get unhappy if it isn't designed for AC.

I'm not really motivated enough to dig through
transformers/plugpacks or rig up an amplifier for my function
generator in order to test with various AC voltages. Especially as
I'm not sure how you'd be sure that it was meant for them even if it
worked to some extent. How would you know how hot the coil is meant
to get for example?

If you can see into the relay, assuming transparent case. You will
see a copper shading ring around the top of the pole piece on an AC
relay. This shading ring will also create the slugging effect that
you describe when using DC on an AC relay.

It has a clear case, but comparing to a known 32VDC V23154-C series
relay I can't see any difference as you describe. I don't have an AC
relay of the same design to compare though.

When I have more time, I'll try to find one of those free image
hoasting sites and put some pictures up.

The shading ring effectively creates a short circuit turn in which the
eddy current magnetic field holds the armature down. A similar effect
to dropping a copper coin between two magnets.

--
Best Regards:
Baron.

 

[Computer Nerd Kev]

Computer Nerd Kev <not@telling.you.invalid> wrote:

When I have more time, I'll try to find one of those free image hoasting
sites and put some pictures up.

Here are some pictures. TinyPic kept throwing up server errors, so I switched
to "Image Posting" after the second picture.

http://i57.tinypic.com/25f3yxl.jpg

http://i61.tinypic.com/n1uxlf.jpg

http://s11.postimg.org/84nxjwvir/p1010067.jpg

http://s7.postimg.org/h7dildj0r/p1010068.jpg

http://s24.postimg.org/ksay77mit/p1010069.jpg

http://s15.postimg.org/lmfe76yi3/p1010070.jpg

--
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#_ < |\| |< _#

 

[Baron]

Computer Nerd Kev scribbled thus:

Computer Nerd Kev <not@telling.you.invalid> wrote:
When I have more time, I'll try to find one of those free image
hoasting sites and put some pictures up.

Here are some pictures. TinyPic kept throwing up server errors, so I
switched to "Image Posting" after the second picture.

http://i57.tinypic.com/25f3yxl.jpg

http://i61.tinypic.com/n1uxlf.jpg

http://s11.postimg.org/84nxjwvir/p1010067.jpg

http://s7.postimg.org/h7dildj0r/p1010068.jpg

http://s24.postimg.org/ksay77mit/p1010069.jpg

http://s15.postimg.org/lmfe76yi3/p1010070.jpg

Hi Kev,
Thanks for the pics. I see no sign of shading rings ! So those would
seem to be DC telecom type relays. If so I would have thought that the
coil voltage would be more like 48 volts.

You could try putting say 12 volts AC across the coil. If they turn
into buzzers then they are definitely DC only.

--
Best Regards:
Baron.

 

[Computer Nerd Kev]

Baron <baron@linuxmaniac.net> wrote:

Thanks for the pics. I see no sign of shading rings ! So those would
seem to be DC telecom type relays. If so I would have thought that the
coil voltage would be more like 48 volts.

They still work at 12V (just). That would be a pretty wide range of
operating voltage.

You could try putting say 12 volts AC across the coil. If they turn
into buzzers then they are definitely DC only.

That they do.

--
__ __
#_ < |\| |< _#

 

[Baron]

Computer Nerd Kev scribbled thus:

Baron <baron@linuxmaniac.net> wrote:
Thanks for the pics. I see no sign of shading rings ! So those
would seem to be DC telecom type relays. If so I would have thought
that the coil voltage would be more like 48 volts.

They still work at 12V (just). That would be a pretty wide range of
operating voltage.

You could try putting say 12 volts AC across the coil. If they turn
into buzzers then they are definitely DC only.

That they do.

That confirms that they are DC only and dont have a diode across the
coil. So it seems that they are 24 volt actuated.

--
Best Regards:
Baron.

 

[Computer Nerd Kev]

Baron <baron@linuxmaniac.net> wrote:

Computer Nerd Kev scribbled thus:

Baron <baron@linuxmaniac.net> wrote:
You could try putting say 12 volts AC across the coil. If they turn
into buzzers then they are definitely DC only.

That they do.

That confirms that they are DC only and dont have a diode across the
coil. So it seems that they are 24 volt actuated.

OK, I'll keep my "prob. 24V" stickers on their component draws then.

Thanks for the help.

--
__ __
#_ < |\| |< _#

 

[Baron]

Computer Nerd Kev scribbled thus:

Baron <baron@linuxmaniac.net> wrote:
Computer Nerd Kev scribbled thus:

Baron <baron@linuxmaniac.net> wrote:
You could try putting say 12 volts AC across the coil. If they
turn into buzzers then they are definitely DC only.

That they do.

That confirms that they are DC only and dont have a diode across the
coil. So it seems that they are 24 volt actuated.

OK, I'll keep my "prob. 24V" stickers on their component draws then.

Thanks for the help.

Your welcome ! Glad to have helped.

--
Best Regards:
Baron.