35Volt MOV testing

[Jamie Morken]

Hi,

I tested some MOV's, part#: ROV10-560K-S

http://www.mouser.com/Search/ProductDetail.aspx?qs=QV10cN0MjFtgsJoeBrrQMQ==

These are called 35Volt MOV's, and I tested 20 of them with my bench
supply set to 61VDC, and the minimum current was about 10mA, and the max
current was about 50mA, with the vast majority in the 10mA to 20mA
range. With 57VDC across them, none of the MOV's had any noticeable
current through them (less than 1mA indicated on the bench supply).

I would like to use MOV's to protect my electronics, these ones seem
perfect to protect a max 60VDC cap bank. Why are these MOV's rated 35V?
I guess this is an AC rating, so 1.7*35VAC=59.5VDC peak, makes sense I
guess Is it acceptable (for UL certification) to use these 35V MOV's
to protect a 60VDC cap bank in a battery charger/inverter application?

I was under the impression that MOV's weren't very accurate but these
ones all seem to be pretty close in tolerances.

cheers,
Jamie

 

[Jamie Morken]

Hi,

I tested some MOV's, part#: ROV10-560K-S

http://www.mouser.com/Search/ProductDetail.aspx?qs=QV10cN0MjFtgsJoeBrrQMQ==


These are called 35Volt MOV's, and I tested 20 of them with my bench
supply set to 61VDC, and the minimum current was about 10mA, and the max
current was about 50mA, with the vast majority in the 10mA to 20mA
range. With 57VDC across them, none of the MOV's had any noticeable
current through them (less than 1mA indicated on the bench supply).

I would like to use MOV's to protect my electronics, these ones seem
perfect to protect a max 60VDC cap bank. Why are these MOV's rated 35V?
I guess this is an AC rating, so 1.7*35VAC=59.5VDC peak, makes sense I
guess Is it acceptable (for UL certification) to use these 35V MOV's
to protect a 60VDC cap bank in a battery charger/inverter application?

I was under the impression that MOV's weren't very accurate but these
ones all seem to be pretty close in tolerances.

that part has a 110Volt clamping voltage, this makes it pretty useless
to protect the 60VDC cap bank I think, is there an "active clamp"
circuit that is used to replace MOV's?

cheers,
Jamie

 

[Hammy]

that part has a 110Volt clamping voltage, this makes it pretty useless
to protect the 60VDC cap bank I think, is there an "active clamp"
circuit that is used to replace MOV's?

cheers,
Jamie

Whats wrong with a TVS zener .Heres a 600W one with a breakdown at
56.7V max leakage 5uA.0.18 CENTS.

http://canada.newark.com/48F5920/semiconductors-discretes/product.us0?sku=littelfuse-smbj51a

 

[Phil Allison]

"Jamie Morken"

I tested some MOV's, part#: ROV10-560K-S

http://www.mouser.com/Search/ProductDetail.aspx?qs=QV10cN0MjFtgsJoeBrrQMQ==

These are called 35Volt MOV's, and I tested 20 of them with my bench
supply set to 61VDC, and the minimum current was about 10mA, and the max
current was about 50mA, with the vast majority in the 10mA to 20mA range.
With 57VDC across them, none of the MOV's had any noticeable current
through them (less than 1mA indicated on the bench supply).

I would like to use MOV's to protect my electronics, these ones seem
perfect to protect a max 60VDC cap bank. Why are these MOV's rated 35V? I
guess this is an AC rating, so 1.7*35VAC=59.5VDC peak,

** Huh ???

Since when in the peak of a sine wave 1.7 times the rms value ??

Is it acceptable (for UL certification) to use these 35V MOV's to protect
a 60VDC cap bank in a battery charger/inverter application?

** Leeme tell ya something - dick brain.

ONLY a retarded, rabid, steaming GREAT FUCKWIT would use a fucking stupid
MOV to "protect " a bank of bloody PSU electros.

What the hell are YOU ?????




....... Phil

 

[[email protected]]

"Jamie Morken"



** Huh ???

Since when in the peak of a sine wave 1.7 times the rms value ??


** Leeme tell ya something - dick brain.

ONLY a retarded, rabid, steaming GREAT FUCKWIT would use a fucking stupid
MOV to "protect " a bank of bloody PSU electros.

What the hell are YOU ?????

...... Phil

Good to see you back in top form, Phil. Do you prepare your screeds
ahead of time and paste them in or are they truly, off-the-cuff word
jazz?

 

[bud--]

Hi,

I tested some MOV's, part#: ROV10-560K-S

http://www.mouser.com/Search/ProductDetail.aspx?qs=QV10cN0MjFtgsJoeBr...

These are called 35Volt MOV's, and I tested 20 of them with my bench
supply set to 61VDC, and the minimum current was about 10mA, and the max
current was about 50mA, with the vast majority in the 10mA to 20mA
range. With 57VDC across them, none of the MOV's had any noticeable
current through them (less than 1mA indicated on the bench supply).

I would like to use MOV's to protect my electronics, these ones seem
perfect to protect a max 60VDC cap bank. Why are these MOV's rated 35V?
I guess this is an AC rating, so 1.7*35VAC=59.5VDC peak, makes sense I
guess Is it acceptable (for UL certification) to use these 35V MOV's
to protect a 60VDC cap bank in a battery charger/inverter application?

I was under the impression that MOV's weren't very accurate but these
ones all seem to be pretty close in tolerances.

What are you protecting the caps from?
Why does UL care?

 

[Rich Grise]

...
I was under the impression that MOV's weren't very accurate but these
ones all seem to be pretty close in tolerances.

MOVs are crap. You should use Transzorbs. I know this from experience
because I worked at a place that had a lot of HV electronics, and there
were MOVs all over the place - when Transzorbs came out, they were SO
much better that the PHB ordered an EO to rip out all of the MOVs and
replace them with Transzorbs.
http://www.vishay.com/diodes/protection-tvs-esd/trans-zorb/

I don't have any kind of affiliation with Vishay - in fact, they weren't
even the ones who initially introduced them (I think it was General
Instruments or some such); I'm just a satisfied customer.

Cheers!
Rich

 

[neon]

Lets face it you have no idea of what is needed . putting moves zeners clamps across capacitors is just very lame. it is like putting them across a battery.What good are they there any surge the caps will dissipate for a while if it persists then nothing will save those caps or the moves.

 

[Jamie Morken]

"Jamie Morken"



** Huh ???

Since when in the peak of a sine wave 1.7 times the rms value ??




** Leeme tell ya something

Hi Phil,

Right after that first sentence I knew it was you, good to see you back,
I've missed your unique electronics advice.

cheers,
Jamie


- dick brain.

 

[Jamie Morken]

What are you protecting the caps from?
Why does UL care?

In UL1741, section 53,
"a) Ten applications of a 6 kV surge impulse at 60 second intervals."

This is applied to a the output of a grid inverter, but I think similar
surges are applied to battery terminals. UL is a huge pain that they
don't have publicly available documents!!! I am trying to access the
UL943 which shows the surge generator circuit that is used to apply
these 6kV pulses..

cheers,
Jamie

 

[ehsjr]

Hi,

I tested some MOV's, part#: ROV10-560K-S

http://www.mouser.com/Search/ProductDetail.aspx?qs=QV10cN0MjFtgsJoeBrrQMQ==


These are called 35Volt MOV's, and I tested 20 of them with my bench
supply set to 61VDC, and the minimum current was about 10mA, and the max
current was about 50mA, with the vast majority in the 10mA to 20mA
range. With 57VDC across them, none of the MOV's had any noticeable
current through them (less than 1mA indicated on the bench supply).

I would like to use MOV's to protect my electronics, these ones seem
perfect to protect a max 60VDC cap bank. Why are these MOV's rated 35V?
I guess this is an AC rating, so 1.7*35VAC=59.5VDC peak, makes sense I
guess Is it acceptable (for UL certification) to use these 35V MOV's
to protect a 60VDC cap bank in a battery charger/inverter application?

I was under the impression that MOV's weren't very accurate but these
ones all seem to be pretty close in tolerances.

cheers,
Jamie

Your test at 61 volts is meaningless. Read up on
MOV ratings & how they are tested.
All your 57 volt, no current test shows is that the
MOVs are not shorted. MOV is not a good choice to
protect against overvoltage, which appears to be what
you have in mind. Think transient protection, not
overvoltage.

Ed