Will a UPS protect against instantaneous voltage drops?

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Hi all,

Due to a control-freak landlord, who asserts that
numerous instantaneous voltage drops occurring whenever
a large appliance is used is "normal" (he's from China)
I feel a need to protect my electronic equipment.
However I am wondering if all UPS devices work
as I hope. My fear is that UPSes have a delay before
they kick in, and that let's say a few thousand individual
millisecond downward dips within 5 seconds won't be
protected against. Or what if the UPS can be damaged
by that?

For instance, I see many here. They're cheap
but will they work?
http://www.circuitcity.com/ssm/Audi.../ups/searchType/user/rpem/ccd/categorylist.do

Thanks.

 

[Steve Noll]

Hi all,

Due to a control-freak landlord, who asserts that
numerous instantaneous voltage drops occurring whenever
a large appliance is used is "normal" (he's from China)
I feel a need to protect my electronic equipment.
However I am wondering if all UPS devices work
as I hope. My fear is that UPSes have a delay before
they kick in, and that let's say a few thousand individual
millisecond downward dips within 5 seconds won't be
protected against. Or what if the UPS can be damaged
by that?

For instance, I see many here. They're cheap
but will they work?
http://www.circuitcity.com/ssm/Audi.../ups/searchType/user/rpem/ccd/categorylist.do

Thanks.

I would get a double-conversion UPS with zero switchover time like a
Tripplite SU750XL. This is a 750VA pure sine wave
double conversion tower unit. Maintains voltage +/-2%, zero
switchover time. Probably can't get better isolation from the power
line. It's their smallest double-conversion unit. Goes for about
$350. The downside is the fan. It has a loud fan that runs
constantly, even when all loads are disconnected.
Steve Noll | The Used Hi Tech Equipment Dealer Directory:
| http://www.big-list.com

 

[Chris]

Hi all,

Due to a control-freak landlord, who asserts that
numerous instantaneous voltage drops occurring whenever
a large appliance is used is "normal" (he's from China)
I feel a need to protect my electronic equipment.
However I am wondering if all UPS devices work
as I hope. My fear is that UPSes have a delay before
they kick in, and that let's say a few thousand individual
millisecond downward dips within 5 seconds won't be
protected against. Or what if the UPS can be damaged
by that?

For instance, I see many here. They're cheap
but will they work?http://www.circuitcity.com/ssm/Audio-Accessories/sem/rpsm/catOid/-129...

Thanks.

You're right in worrying about switchover time -- that can be an issue
with a standard UPS and voltage sag/surge. The UPS supplies shown
will have a problem here.

A lower tech solution than the good one mentioned by Steve (and that
doesn't have the annoyance of fan noise or batteries to periodically
replace) is a simple constant voltage transformer. You're guaranteed
regulation within a couple of percent for input voltages from 80% to
110% of nominal line voltage, and there are no moving or wear parts --
they last virtually forever. Only downside is that, in the event of
power interruption, you're not protected. That's where the small UPS
comes in, if you need that capability.

Look at Surplus Sales of Nebraska for a couple of used ones that
should do the job -- particularly (TP) 23-13-150 for a 500VA model
for $125 USD and (TP) 20-13-125 for a 250VA model for $85:

http://www.surplussales.com/PowerSupplies/PowerS-1.html

Of course, you'll have to pay shipping, too. :-(

Cheers
Chris

 

[John Fields]

You're right in worrying about switchover time -- that can be an issue
with a standard UPS and voltage sag/surge. The UPS supplies shown
will have a problem here.

A lower tech solution than the good one mentioned by Steve (and that
doesn't have the annoyance of fan noise or batteries to periodically
replace) is a simple constant voltage transformer. You're guaranteed
regulation within a couple of percent for input voltages from 80% to
110% of nominal line voltage, and there are no moving or wear parts --
they last virtually forever. Only downside is that, in the event of
power interruption, you're not protected. That's where the small UPS
comes in, if you need that capability.

---
Problem with that scheme is it leaves him in the same position he'd
be in in the first place. That is, with a gap in time between when
power went out and the UPS kicked in.

For real protection he'll need a solution using an on-line UPS like
Steve suggested.

 

[Jamie]

Hi all,

Due to a control-freak landlord, who asserts that
numerous instantaneous voltage drops occurring whenever
a large appliance is used is "normal" (he's from China)
I feel a need to protect my electronic equipment.
However I am wondering if all UPS devices work
as I hope. My fear is that UPSes have a delay before
they kick in, and that let's say a few thousand individual
millisecond downward dips within 5 seconds won't be
protected against. Or what if the UPS can be damaged
by that?

For instance, I see many here. They're cheap
but will they work?
http://www.circuitcity.com/ssm/Audi.../ups/searchType/user/rpem/ccd/categorylist.do

Thanks.

well it'd like this

I have a UPS that I paid only 85 bucks new for and it's a double
conversion. I've even had the opportunity to test it with a desk light
I happen to have on the circuit as well as computer and monitor..
this last summer we lost power, several brown outs before that and
the system was perfectly stable maintaining voltage in the brown outs
and no delay issues since the inverter is 100% .. the only issue I have
with that one is the output freq.. It's 60.7 Hz, My old digital clock
that I love some much gains a little time ..

My expensive one, 1100 Watts, does not operate this way.. oh well.

 

[Stephen J. Rush]

catOid/-12927/Ntk/Champion/Ntt/ups/searchType/user/rpem/ccd/
categorylist.do
well it'd like this

I have a UPS that I paid only 85 bucks new for and it's a double
conversion. I've even had the opportunity to test it with a desk light I
happen to have on the circuit as well as computer and monitor..
this last summer we lost power, several brown outs before that and
the system was perfectly stable maintaining voltage in the brown outs
and no delay issues since the inverter is 100% .. the only issue I have
with that one is the output freq.. It's 60.7 Hz, My old digital clock
that I love some much gains a little time ..

Have you looked for a frequency trimmer, or the option to synchronize the
inverter to an external source?

 

[Jamie]

Have you looked for a frequency trimmer, or the option to synchronize the
inverter to an external source?

Nope, getting ready to buy another anyway. Almost 2 years old, time for
a new unit before the battery goes south on this one.

I've got caught with my paints down before! never again!