, Cornwall. TR10 9LU. UK
T: 01326 372070
E: ian.mcbur...@allen-heath.com
From: Richard Nute [mailto:ri...@ieee.org]
Sent: 13 December 2013 20:06
To: McBurney, Ian; EMC-PSTC@LISTSERV.IEEE.ORG
Subject: Re: [PSES] Cooling fan safety query
Hello Ian:
The first question is whether or not the fan
]
*Sent:* 13 December 2013 20:06
*To:* McBurney, Ian; EMC-PSTC@LISTSERV.IEEE.ORG
*Subject:* Re: [PSES] Cooling fan safety query
Hello Ian:
The first question is whether or not the fan is necessary
to meet the temperature requirements of the standard.
If yes, then the fan and its alternates must
From: Richard Nute
Sent: Monday, December 16, 2013 11:03
Stalling the fan would be the better course of action
as this would require the fan motor to dissipate some
power as well as the series resistor, thus causing
more heat -- but not much -- in the equipment.
My experience with small
[mailto:ri...@ieee.org]
Sent: 13 December 2013 20:06
To: McBurney, Ian; EMC-PSTC@LISTSERV.IEEE.ORGmailto:EMC-PSTC@LISTSERV.IEEE.ORG
Subject: Re: [PSES] Cooling fan safety query
Hello Ian:
The first question is whether or not the fan is necessary
to meet the temperature requirements
This is a question for the safety testing engineers.
We have products that contain 12V/24V DC cooling fans that cool either the PSU
or processing circuits.
The fan speeds are reduced with basically a series resistor to reduce audio
noise.
The safety testing agency demands to know the exact
In message
80f690de07894e049b221728b4a99...@dbxpr07mb206.eurprd07.prod.outlook.com
, dated Fri, 13 Dec 2013, McBurney, Ian ian.mcbur...@allen-heath.com
writes:
We have to use alternative fans due to supply issues and this incurs
considerable test agency costs as the agency won?t accept a
-
From: John Woodgate [mailto:j...@jmwa.demon.co.uk]
Sent: 13 December 2013 10:34
To: EMC-PSTC@LISTSERV.IEEE.ORG
Subject: Re: [PSES] Cooling fan safety query
In message
80f690de07894e049b221728b4a99...@dbxpr07mb206.eurprd07.prod.outlook.com
, dated Fri, 13 Dec 2013, McBurney, Ian ian.mcbur...@allen
In message
ed08bb5be2d841e0a1b0ca499f924...@dbxpr07mb206.eurprd07.prod.outlook.com
, dated Fri, 13 Dec 2013, McBurney, Ian ian.mcbur...@allen-heath.com
writes:
I believe the fans are listed for the flammability of the plastic body
but I may be wrong.
It would surely be worthwhile to check
.
-Original Message-
From: John Woodgate [mailto:j...@jmwa.demon.co.uk]
Sent: 13 December 2013 11:23
To: EMC-PSTC@LISTSERV.IEEE.ORG
Subject: Re: [PSES] Cooling fan safety query
In message
ed08bb5be2d841e0a1b0ca499f924...@dbxpr07mb206.eurprd07.prod.outlook.com
, dated Fri, 13 Dec 2013
.
Regards
John Allen
Compliance with Experience
W.London. UK
-Original Message-
From: McBurney, Ian [mailto:ian.mcbur...@allen-heath.com]
Sent: 13 December 2013 11:05
To: EMC-PSTC@LISTSERV.IEEE.ORG
Subject: Re: [PSES] Cooling fan safety query
John;
I believe the fans are listed
.
Regards
John Allen
Compliance with Experience
W.London. UK
-Original Message-
From: McBurney, Ian [mailto:ian.mcbur...@allen-heath.com]
Sent: 13 December 2013 11:05
To: EMC-PSTC@LISTSERV.IEEE.ORG
Subject: Re: [PSES] Cooling fan safety query
John;
I believe the fans are listed
[mailto:ian.mcbur...@allen-heath.com]
Sent: 13 December 2013 13:55
To: John Allen; EMC-PSTC@LISTSERV.IEEE.ORG
Subject: RE: [PSES] Cooling fan safety query
John;
I agree the airflow rates will vary with applied voltage and blade profile
but if the product continues to function safely with a stalled rotor why
In message
ff0018ae2af54a2b95bfa760f8747...@dbxpr07mb206.eurprd07.prod.outlook.com
, dated Fri, 13 Dec 2013, McBurney, Ian ian.mcbur...@allen-heath.com
writes:
but if the product continues to function safely with a stalled rotor
why does it have to be listed in the critical component list.
2013 14:18
To: EMC-PSTC@LISTSERV.IEEE.ORG
Subject: Re: [PSES] Cooling fan safety query
In message
ff0018ae2af54a2b95bfa760f8747...@dbxpr07mb206.eurprd07.prod.outlook.com
, dated Fri, 13 Dec 2013, McBurney, Ian ian.mcbur...@allen-heath.com
writes:
but if the product continues to function safely
to privilege
have not been waived.
.
-Original Message-
From: McBurney, Ian [mailto:ian.mcbur...@allen-heath.com]
Sent: Friday, December 13, 2013 8:55 AM
To: EMC-PSTC@LISTSERV.IEEE.ORG
Subject: Re: [PSES] Cooling fan safety query
John;
I agree the airflow rates will vary with applied
In message
c8225bb6612e4cf382ba4b073e71d...@dbxpr07mb206.eurprd07.prod.outlook.com
, dated Fri, 13 Dec 2013, McBurney, Ian ian.mcbur...@allen-heath.com
writes:
I have often asked for the reasoning to many similar problems and get
directed to an ambiguous clause in the standard that I read one
n.mcbur...@allen-heath.com]
>Sent: Friday, December 13, 2013 8:55 AM
>To: EMC-PSTC@LISTSERV.IEEE.ORG
>Subject: Re: [PSES] Cooling fan safety query
>
>John;
>
>I agree the airflow rates will vary with applied voltage and blade profile but if the product continues to function "safely&quo
: [External] Re: [PSES] Cooling fan safety query
In message
c8225bb6612e4cf382ba4b073e71d...@dbxpr07mb206.eurprd07.prod.outlook.com
, dated Fri, 13 Dec 2013, McBurney, Ian ian.mcbur...@allen-heath.com
writes:
I have often asked for the reasoning to many similar problems and get
directed
: [External] Re: [PSES] Cooling fan safety query
A locked rotor test is considered an abnormal and measured temperatures are
allowed to exceed the limits for normal operation. If that happens, then it
proves a minimal amount of airflow is required to maintain safe temperatures
and minimal CFMs
.
Regards
John Allen
Compliance with Experience
W.London. UK
-Original Message-
From: McBurney, Ian [mailto:ian.mcbur...@allen-heath.com]
Sent: 13 December 2013 11:05
To: EMC-PSTC@LISTSERV.IEEE.ORG
Subject: Re: [PSES] Cooling fan safety query
John;
I believe the fans are listed
Ian -
Another consideration, since you have more than one fan, is that you can
disable *all* fans simultaneously to demonstrate that no cooling is
necessary for safety reasons. This is a multiple fault scenario, but it's
at your discretion to do so to prove your case and eliminates the need for
Hello Ian:
The first question is whether or not the fan is necessary
to meet the temperature requirements of the standard.
If yes, then the fan and its alternates must be tested to
prove that the end-product meets the temperature requirements.
A UL-certified fan should reduce the testing
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