Manage load shedding

[bones]

Ian do you have a laser cutter
how do you keep the thing
from crashing?

[IanF]

Hi Bones,
That USB adapter looks good so you can use it on the desktop as well. I will look at that later.
For the laser cutter it is a chinese one and one thing is when the power goes it just stops. Then when the power comes back you just switch it back on and it restarts in exactly the same place and finishes the job. Then we also bought a voltage regulator for the laser and it just runs no hassle and the current tube has been going for 2 years.

[bones]

Hi Bones,
That USB adapter looks good so you can use it on the desktop as well. I will look at that later.
For the laser cutter it is a chinese one and one thing is when the power goes it just stops. Then when the power comes back you just switch it back on and it restarts in exactly the same place and finishes the job. Then we also bought a voltage regulator for the laser and it just runs no hassle and the current tube has been going for 2 years.

mine was secondhand to start with
then got in the way of some vandals
got it working but it freezes a lot

power dip finally put it out of my
misery at 3:20 pm today i am looking
for one now any suggestions?

got a tight budget for something
basic

[bones]

i saw one for about R51k not
bad looking systems

http://am.co.za/laser

[IanF]

Bones, I have an aversion to software dongles but would go and have a demo on that machine as it is a good price. I got my machine from astroware and here is a link to a similar one. Then also get some thing to control the power spikes.
I got my last tube from perfect laser but haven't had to replace yet. They also sell machines.

[bones]

Bones, I have an aversion to software dongles but would go and have a demo on that machine as it is a good price. I got my machine from astroware and here is a link to a similar one. Then also get some thing to control the power spikes.
I got my last tube from perfect laser but haven't had to replace yet. They also sell machines.

will have a look our rand is not helping
my wife pointed out we can send laser
work out or just stop doing it she is
right since we got 2ns hand laser we
never recovered the cost

will sleep on it did the laptop thing got
to 2 elcheapo systems and only use
the AMD for the bigger jobs but i found
it is mostly off i dont use it

if you thinking of doing the laptop dance
start with one and force yourself to use
it i3 is more then enough for basic stuff
i did the 6gb ram thing that is a must

powered USB hub is a must have

[bones]

right power is out laptops are
working just fine but i cannot
do a bloody thing because
the ups on my printer died
before the generator kicked
in and something got damaged
it doesnt want to turn on
it is under contract they will
fix it tomorrow

some advice stay away from
shitty upss

[IanF]

Bones is it a laser printer I should imagine that will kill most upss. I hope that you don't have a big bill as some printer parts are priced like gold.

[Justloadit]

some advice stay away from
shitty upss

Define a "shitty ups"?
and
how to identify a "shitty ups"?

There are many reasons that can cause the failure, which one may not be aware off.
1. Surge - caused by lightning or disconnection of a electrical grid, as in the case of load shedding
2. Battery discharge to quickly - a number of reasons, such as to many cycles, not sufficient time for battery to charge, old battery, incorrect size battery for internal charger, unsed battery for many years now put into service, flat battery left uncharged for many days, temperature during charge and discharge.
3. Load too large for battery capacity
4. Operational start up currents exceed UPS rating
5. In coming mains out of spec to UPS, and UPS wants to run off flat battery and then shuts down
6. In coming supply unstable as in the case of a genny which is too small for the application - oscillating voltage and frequency as genny has a mechanical governor
7. Replacement battery not deep cycle battery

and so the list can go on.

In general I have found that most UPS are acceptable if used with in the specifications they were designed for, the usual discontent is the load over powers the UPS, and in the cheaper models, they used cheap batteries and not the deep cycle as is recommended. Effectively UPS were designed to allow one to save work on PCs in the case of a power failure, which occurs rarely in most countries, however in the case of RSA, this is now taking the equipment out of its design parameters.

[bones]

Bones is it a laser printer I should imagine that will kill most upss. I hope that you don't have a big bill as some printer parts are priced like gold.

was the laser yes but im renting
it owning them is just not
economical anymore it will be
the power supply 100% sure it
is not the first time

shity ups was never meant to
keep it alive just allow it the
30sec to switch over from
mains to gen

but the ups was cheap thing
from the local pc store they
warned me it will not hold
the laser

i will look into a inverter saw one
at a hardware store few weeks
ago it is a 2kwatt system with
large batteries it basically is a
massive ups

[bones]

Define a "shitty ups"?
and
how to identify a "shitty ups"?

There are many reasons that can cause the failure, which one may not be aware off.
1. Surge - caused by lightning or disconnection of a electrical grid, as in the case of load shedding
2. Battery discharge to quickly - a number of reasons, such as to many cycles, not sufficient time for battery to charge, old battery, incorrect size battery for internal charger, unsed battery for many years now put into service, flat battery left uncharged for many days, temperature during charge and discharge.
3. Load too large for battery capacity
4. Operational start up currents exceed UPS rating
5. In coming mains out of spec to UPS, and UPS wants to run off flat battery and then shuts down
6. In coming supply unstable as in the case of a genny which is too small for the application - oscillating voltage and frequency as genny has a mechanical governor
7. Replacement battery not deep cycle battery

and so the list can go on.

In general I have found that most UPS are acceptable if used with in the specifications they were designed for, the usual discontent is the load over powers the UPS, and in the cheaper models, they used cheap batteries and not the deep cycle as is recommended. Effectively UPS were designed to allow one to save work on PCs in the case of a power failure, which occurs rarely in most countries, however in the case of RSA, this is now taking the equipment out of its design parameters.

3 and 4 killed it im 100% sure
im to blame for this mess
sh_t will happen that said my
generator normally kicks in
asap will look why it didnt
this time

rsa is demadning a lot from
our stuff they are not build
for this mess

[ians]

It is not a wise investment using diy generators for fixed installations or electronic equipment. The sine wave is a serious issue, never mind the voltage regulation. The other issue is the frequency. Most equipment like a UPS is designed to run with a .5 hz tolerance. You can purchase UPS units which are capable of operation between 45 hz and 55 hz.

[CLIVE-TRIANGLE]

Can someone explain why this is:
I have a small 1200 watt UPS; it only powers a few things, ADSL router, Network attached storage and an Airport Wireless access point. It is able to keep that lot going for more than 90 minutes.

Because I needed more than 90 minutes, I acquired a 2000 watt Emergency Power Supply with a generous battery bank. This I connected as the supply to the UPS.

However, when the power is off, the UPS is not supplied by the EPS; it's as if it is not there and the UPS will run on battery only. Obviously when there is mains, no problem.

I am too dumb to figure out why this is.

[Dave A]

Probably a case of the UPS rejecting the quality of the supply from the EPS. Could be voltage, frequency or wave form that's the problem.

[AndyD]

UPS's are a device that detect power failure and switch to backup batteries very quickly, so quickly in fact that the devices connected to them don't even know that there was a momentary power failure. When you have a UPS that's supplied by another UPS, because of the speed required, their sensing of power fail is so fast that both UPS's will go into battery back-up mode immediately.

Once this happens the downstream UPS will switch back to normal mode if it is happy with the power that's being delivered to it by the upstream UPS. If the upstream UPS is delivering power that's anything less than spotlessly clean and pure sine wave then the downstream UPSis probly not going to see this as acceptable power being restored so it's staying in power fail mode.

Supplying one UPS from another UPS is something that's best avoided at all costs unless they're known to be compatible units. Even then it's a less efficient way than just having a single larger UPS. The better option would be to either extend the battery bank of your original UPS if its built-in charger can handle extra batteries or to replace the original UPS entirely with one that's the same KVA rating and has a bigger battery pack and longer run time and sell or redeploy the original one.