Power supply w/o ground

J

JT

Guest
A small open-frame line powered power supply (Cincom CFM05S033) doesn't have
a ground connection. It will power a tiny device which only has +3.3V/0V DC
connections. This will be used in a 6x6x4 plastic enclosure so there is no
chassis ground. An electrician will be wiring it in.

Is this inherently unsafe? Do I need to find another supply with a ground?
 
"JT" <JT1234@yahoo.com> wrote in message
news:ec631$46f824ad$d8447b12$8914@FUSE.NET...
A small open-frame line powered power supply (Cincom CFM05S033) doesn't
have a ground connection. It will power a tiny device which only has
+3.3V/0V DC connections. This will be used in a 6x6x4 plastic enclosure so
there is no chassis ground. An electrician will be wiring it in.

Is this inherently unsafe? Do I need to find another supply with a ground?
I assume you are asking about Earth Grounds. Some devices operate safely
with them. You should be go to go ... but it depends on worst cases and
possible litigation.
 
Charles wrote:
"JT" <JT1234@yahoo.com> wrote in message
news:ec631$46f824ad$d8447b12$8914@FUSE.NET...
A small open-frame line powered power supply (Cincom CFM05S033) doesn't
have a ground connection. It will power a tiny device which only has
+3.3V/0V DC connections. This will be used in a 6x6x4 plastic enclosure so
there is no chassis ground. An electrician will be wiring it in.

Is this inherently unsafe? Do I need to find another supply with a ground?

I assume you are asking about Earth Grounds. Some devices operate safely
with them. You should be go to go ... but it depends on worst cases and
possible litigation.

WTH is 'go to go'? It's time to up your meds, again. ;(


--
Service to my country? Been there, Done that, and I've got my DD214 to
prove it.
Member of DAV #85.

Michael A. Terrell
Central Florida
 
JT wrote:

A small open-frame line powered power supply (Cincom CFM05S033) doesn't have
a ground connection. It will power a tiny device which only has +3.3V/0V DC
connections. This will be used in a 6x6x4 plastic enclosure so there is no
chassis ground. An electrician will be wiring it in.

Is this inherently unsafe? Do I need to find another supply with a ground?
Where did you expect to see a GROUND and why ?

Plenty of power supplies don't have them and don't need them. See Class II
insulation.
http://en.wikipedia.org/wiki/Appliance_classes

Graham
 
On Sep 24, 3:57 pm, "JT" <JT1...@yahoo.com> wrote:
A small open-frame line powered power supply (Cincom CFM05S033) doesn't have
a ground connection. It will power a tiny device which only has +3.3V/0V DC
connections. This will be used in a 6x6x4 plastic enclosure so there is no
chassis ground. An electrician will be wiring it in.

Is this inherently unsafe? Do I need to find another supply with a ground?
The AC-to-DC switching regulator power supply you're using has an
isolated output, meaning it's constructed so there's no inherent
connection between either the positive or negative end of the 3.3VDC
supply and anything else.

Actually, the data sheet suggests there's more than 4KV isolation
between the line voltage input side and the output. I'd take that
with a grain of salt, but it does tell you there's no inherent danger
involved in either leaving the supply output floating, or grounding
it.

If you need a grounded supply (think twice before doing this unless
you have to -- most times, in industrial applications grounding the
supply causes more difficulty than it solves), you can just connect
the earth ground wire to the negative terminal of the supply (or the
positive terminal, for that matter).
 
"Michael A. Terrell" <mike.terrell@earthlink.net> wrote in message
news:46F835E0.AA57E922@earthlink.net...
Charles wrote:

"JT" <JT1234@yahoo.com> wrote in message
news:ec631$46f824ad$d8447b12$8914@FUSE.NET...
A small open-frame line powered power supply (Cincom CFM05S033) doesn't
have a ground connection. It will power a tiny device which only has
+3.3V/0V DC connections. This will be used in a 6x6x4 plastic enclosure
so
there is no chassis ground. An electrician will be wiring it in.

Is this inherently unsafe? Do I need to find another supply with a
ground?

I assume you are asking about Earth Grounds. Some devices operate safely
with them. You should be go to go ... but it depends on worst cases and
possible litigation.


WTH is 'go to go'? It's time to up your meds, again. ;(
Surely the Great Terrell can figure that out?
 
"JT"
A small open-frame line powered power supply (Cincom CFM05S033) doesn't
have a ground connection.

** The brand name is " Cincon " - you PITA.





........ Phil
 
"Chris"
Is this inherently unsafe? Do I need to find another supply with a
ground?

The AC-to-DC switching regulator power supply you're using has an
isolated output, meaning it's constructed so there's no inherent
connection between either the positive or negative end of the 3.3VDC
supply and anything else.

Actually, the data sheet suggests there's more than 4KV isolation
between the line voltage input side and the output. I'd take that
with a grain of salt, but it does tell you there's no inherent danger
involved in either leaving the supply output floating, or grounding
it.

** Mere isolation voltage figures tell you .......

NO SUCH DAMN THING !!

A given product is either made to meet "Class 2 " ( ie double insulation)
safety requirements or it is NOT !!

If it is NOT - then all user accessible wiring & exposed metal MUST be
connected to safety ground via a solid wire link.

If a product does not specifically state that it meets all Class 2
ules - NEVER assume.

Someone's life may be on the line.




........ Phil
 
"Phil Allison" <philallison@tpg.com.au> wrote in message
news:5lreh3F9kfssU1@mid.individual.net...
"Chris"


Is this inherently unsafe? Do I need to find another supply with a
ground?

The AC-to-DC switching regulator power supply you're using has an
isolated output, meaning it's constructed so there's no inherent
connection between either the positive or negative end of the 3.3VDC
supply and anything else.

Actually, the data sheet suggests there's more than 4KV isolation
between the line voltage input side and the output. I'd take that
with a grain of salt, but it does tell you there's no inherent danger
involved in either leaving the supply output floating, or grounding
it.


** Mere isolation voltage figures tell you .......

NO SUCH DAMN THING !!

A given product is either made to meet "Class 2 " ( ie double
insulation) safety requirements or it is NOT !!

If it is NOT - then all user accessible wiring & exposed metal MUST
be connected to safety ground via a solid wire link.

If a product does not specifically state that it meets all Class 2
es - NEVER assume.

Someone's life may be on the line.

....... Phil
I am not building a double-insulated Class II device. It is a power supply
in a IP65 plastic enclosure, it can potentially be LOCATED OUTSIDE.

This "Cincon" (sorry Phil if I offended you.???) supply only has 2 tiny pads
exposing the 120VAC to the user, I will cover these with epoxy potting
compound.

Class I says the chassis should be grounded but the chassis is plastic.
There will be an Earth Ground line coming in, should I just connect it to
the AC Neutral terminal?

Or, is this supply specifically design for Class II and I need to find
another?
 
"JT"
"Phil Allison"

** Mere isolation voltage figures tell you .......

NO SUCH DAMN THING !!

A given product is either made to meet "Class 2 " ( ie double
insulation) safety requirements or it is NOT !!

If it is NOT - then all user accessible wiring & exposed metal MUST
be connected to safety ground via a solid wire link.

If a product does not specifically state that it meets all Class 2 es -
NEVER assume.

Someone's life may be on the line.

....... Phil


I am not building a double-insulated Class II device.

** Sure sounds the hell like you ARE to me !!!

Got a clue what one is ??




It is a power supply in a IP65 plastic enclosure, it can potentially be
LOCATED OUTSIDE.

** Nonsense.

External PSU are nearly all required to be Class 2 devices

- by LAW !!!

Take a look at any wall wart or phone charger.



This "Cincon" (sorry Phil if I offended you.???)

** Your dumb spelling error wasted my time on Google.



Class I says the chassis should be grounded but the chassis is plastic.

** Class 1 requires any output connection to be safety EARTHED !!!!!!!!!



Or, is this supply specifically design for Class II and I need to find
another?

** Read my post.

If there are no marking re Class 2 compliance

- it damn well AIN'T !!!!!!!!




........ Phil
 
"Phil Allison"
** Mere isolation voltage figures tell you ....... NO SUCH DAMN
THING !
A given product is either made to meet "Class 2 " ( ie double
insulation) safety requirements or it is NOT !!
If it is NOT - then all user accessible wiring & exposed metal MUST
be connected to safety ground via a solid wire link.
If a product does not specifically state that it meets all Class 2
- NEVER assume.

Someone's life may be on the line.
....... Phil

I am not building a double-insulated Class II device.
** Sure sounds the hell like you ARE to me !!!
Got a clue what one is ??

It is a power supply in a IP65 plastic enclosure, it can potentially be
LOCATED OUTSIDE.
** Nonsense.
External PSU are nearly all required to be Class 2 devices
- by LAW !!!
Take a look at any wall wart or phone charger.
Please clarify "external PSU". You imply...external to the product, like a
wall wart. My design will have the PSU internal to the product. The entire
product and PSU is in the IP65 housing, there are no other connections or
outputs. So I think I am still looking at a Class I device, correct?

Class I says the chassis should be grounded but the chassis is plastic.
** Class 1 requires any output connection to be safety EARTHED
!!!!!!!!!
There are no "outputs".
There will be an Earth Ground conductor coming in, should I just connect it
to
the AC Neutral terminal?

> ....... Phil
 
"JT"
"Phil Allison"

- NEVER assume.

Someone's life may be on the line.


I am not building a double-insulated Class II device.
** Sure sounds the hell like you ARE to me !!!
Got a clue what one is ??

It is a power supply in a IP65 plastic enclosure, it can potentially be
LOCATED OUTSIDE.
** Nonsense.
External PSU are nearly all required to be Class 2 devices
- by LAW !!!
Take a look at any wall wart or phone charger.

Please clarify "external PSU".

** Your " located outside " will do anytime

- FUCKWIT !!!!!!!!!!!!!!!!!!!!!.



You imply...external to the product, like a wall wart. My design will have
the PSU internal to the product.

** Now * I KNOW * you are fuckwit * LIAR * .



The entire product and PSU is in the IP65 housing, there are no other
connections or outputs.


** Nothing at allllllll ???

No user accessible metal parts whateverrrrrrrrr ????

So it does nothing and connects to nothing ???????????


LIKE HELL !!!!!!!!!!!!



So I think I am still looking at a Class I device, correct?

** I reckon you are staring right up you hairy, fat arse.

As usual.



There are no "outputs".

There will be an Earth Ground conductor coming in,

** Why ?????????????????????????????????????


should I just connect it to the AC Neutral terminal?

** If you wanna trip every stinking single ELCB, Core Balance Relay,
Safety Switch and RCD in the entire fucking world.

Yeah - go do that.

IMBECILE !!!!!!!!!!!




....... Phil
 
"Phil Allison" <philallison@tpg.com.au> wrote in message
news:5lsi8mF9quaaU1@mid.individual.net...
"JT"
"Phil Allison"
- NEVER assume.
Someone's life may be on the line.

It is a power supply in a IP65 plastic enclosure, it can potentially be
LOCATED OUTSIDE.
** Nonsense.
External PSU are nearly all required to be Class 2 devices
- by LAW !!!
Take a look at any wall wart or phone charger.
Please clarify "external PSU".
** Your " located outside " will do anytime
- FUCKWIT !!!!!!!!!!!!!!!!!!!!!.
Nice grammar, I haven't a clue what you just said.

You imply...external to the product, like a wall wart. My design will
have the PSU internal to the product.
** Now * I KNOW * you are fuckwit * LIAR * .
Huh?

The entire product and PSU is in the IP65 housing, there are no other
connections or outputs.
** Nothing at allllllll ???
The entire product and PSU are in the IP65 housing, THERE ARE NO OTHER
CONNECTIONS OR OUTPUTS.

No user accessible metal parts whateverrrrrrrrr ????
So it does nothing and connects to nothing ???????????
LIKE HELL !!!!!!!!!!!!
You saw the picture. Sure, the power supply has "metal parts", if you're
counting component leads and solder pads. Your point?

There will be an Earth Ground conductor coming in,
** Why ?????????????????????????????????????
If I don't need an Earth Ground just say so.

should I just connect it to the AC Neutral terminal?
** If you wanna trip every stinking single ELCB, Core Balance Relay,
Safety Switch and RCD in the entire fucking world.
Yeah - go do that.
IMBECILE !!!!!!!!!!!
....hence my questioning of this suggetion from "Chris".

> ...... Phil
 
"JT" <JT1234@yahoo.com> wrote in message
news:ec631$46f824ad$d8447b12$8914@FUSE.NET...
A small open-frame line powered power supply (Cincom CFM05S033) doesn't
have a ground connection. It will power a tiny device which only has
+3.3V/0V DC connections. This will be used in a 6x6x4 plastic enclosure so
there is no chassis ground. An electrician will be wiring it in.

Is this inherently unsafe? Do I need to find another supply with a ground?

Perhaps someone can suggest how to safely wire and enclose a small 3.3V
device with 120VAC power supply for use outdoors.
TIA
 
"JT"
Perhaps someone can suggest how to safely wire and enclose a small 3.3V
device with 120VAC power supply for use outdoors.
TIA

** Totally " pot " the damn thing.

Polyester resin is top stuff.





...... Phil
 
JT wrote:

"Phil Allison" <philallison@tpg.com.au> wrote
"Chris"

Is this inherently unsafe? Do I need to find another supply with a
ground?

The AC-to-DC switching regulator power supply you're using has an
isolated output, meaning it's constructed so there's no inherent
connection between either the positive or negative end of the 3.3VDC
supply and anything else.

Actually, the data sheet suggests there's more than 4KV isolation
between the line voltage input side and the output. I'd take that
with a grain of salt, but it does tell you there's no inherent danger
involved in either leaving the supply output floating, or grounding
it.


** Mere isolation voltage figures tell you .......

NO SUCH DAMN THING !!

A given product is either made to meet "Class 2 " ( ie double
insulation) safety requirements or it is NOT !!

If it is NOT - then all user accessible wiring & exposed metal MUST
be connected to safety ground via a solid wire link.

If a product does not specifically state that it meets all Class 2
es - NEVER assume.

Someone's life may be on the line.

....... Phil

I am not building a double-insulated Class II device.
If it's not Class II then it's presumably Class I which requires an earth.


It is a power supply
in a IP65 plastic enclosure, it can potentially be LOCATED OUTSIDE.

This "Cincon" (sorry Phil if I offended you.???) supply only has 2 tiny pads
exposing the 120VAC to the user, I will cover these with epoxy potting
compound.

Class I says the chassis should be grounded but the chassis is plastic.
There will be an Earth Ground line coming in, should I just connect it to
the AC Neutral terminal?

Or, is this supply specifically design for Class II and I need to find
another?
If you need to ask, quite frankly you shouldn't be building anything like this.

I suggest you read up on safety standards.

Graham
 
JT wrote:

There will be an Earth Ground conductor coming in, should I just connect it
to the AC Neutral terminal?
Frankly, if you think such an idea is even remotely acceptable you deserve to be
shot.

Graham
 
On Tue, 25 Sep 2007 09:43:10 -0400, "JT" <JT1234@yahoo.com> wrote:

<snippage>

There are no "outputs".
There will be an Earth Ground conductor coming in, should I just connect it
to
the AC Neutral terminal?
DO NOT connect the earth ground (safety ground, green or green/yellow
wire) to the neutral in your equipment. The safety ground should be
connected to any exposed metal (or otherwise conductive) parts of your
equipment.

If your device has no exposed metal parts, do not connect the green
(or green/yellow) safety ground to anything.


--
Peter Bennett, VE7CEI
peterbb4 (at) interchange.ubc.ca
new newsgroup users info : http://vancouver-webpages.com/nnq
GPS and NMEA info: http://vancouver-webpages.com/peter
Vancouver Power Squadron: http://vancouver.powersquadron.ca
 
On Tue, 25 Sep 2007 10:22:11 -0400, "JT" <JT1234@yahoo.com> wrote:

"JT" <JT1234@yahoo.com> wrote in message
news:ec631$46f824ad$d8447b12$8914@FUSE.NET...
A small open-frame line powered power supply (Cincom CFM05S033) doesn't
have a ground connection. It will power a tiny device which only has
+3.3V/0V DC connections. This will be used in a 6x6x4 plastic enclosure so
there is no chassis ground. An electrician will be wiring it in.

Is this inherently unsafe? Do I need to find another supply with a ground?


Perhaps someone can suggest how to safely wire and enclose a small 3.3V
device with 120VAC power supply for use outdoors.
TIA

Why not buy a wall wart with the required output? It will be made to
be ungrounded and all the energized parts will be enclosed by the
maker so you won't need to worry. By the way, please don't pay
attention to phil allison. He is probably in need of professional help
but instead spends his time trying to rile up anybody he can online.
Just like when CB radios were a big craze and all sorts of shy whackos
would get their hands on a radio and broadcast all sorts of stuff
pretending to be something or someone they were not.
ERS
 
On Wed, 26 Sep 2007 16:21:40 -0700, Eric R Snow <etpm@whidbey.com>
wrote:

On Tue, 25 Sep 2007 10:22:11 -0400, "JT" <JT1234@yahoo.com> wrote:

"JT" <JT1234@yahoo.com> wrote in message
news:ec631$46f824ad$d8447b12$8914@FUSE.NET...
A small open-frame line powered power supply (Cincom CFM05S033) doesn't
have a ground connection. It will power a tiny device which only has
+3.3V/0V DC connections. This will be used in a 6x6x4 plastic enclosure so
there is no chassis ground. An electrician will be wiring it in.

Is this inherently unsafe? Do I need to find another supply with a ground?


Perhaps someone can suggest how to safely wire and enclose a small 3.3V
device with 120VAC power supply for use outdoors.
TIA

Why not buy a wall wart with the required output? It will be made to
be ungrounded and all the energized parts will be enclosed by the
maker so you won't need to worry. By the way, please don't pay
attention to phil allison. He is probably in need of professional help
but instead spends his time trying to rile up anybody he can online.
Just like when CB radios were a big craze and all sorts of shy whackos
would get their hands on a radio and broadcast all sorts of stuff
pretending to be something or someone they were not.
ERS
I've never noticed his technical advice to be incorrect. Of course, he
doesn't give technical advice as often as he spews abuse.

--
Al in St. Lou
 

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