Hacking APC UPS's "Master/Controlled" Feature?
 

I just bought two APC ES 750s.

The feature set touted on the box cites a "Master" outlet that
controls several "Controlled By Master" outlets.

My expectation was that the "Controlled" outlets would run on
battery until the "Master" device shut down.

The idea is that we can keep the router/switches working while
the NAS is on backup, but that they will not drain the battery
once the NAS shuts down.

Reading other threads, it seems like the "Controlled" outlets are
not really controlled by the master in the case of power loss:
they just shut down immediately.

Direct experience confirms this.


The Question:

Has anybody hacked one of these things so they actually function
as advertised? i.e. when power is lost, the devices connected to
"Controlled By Master" outlets stay powered up until the device
connected to the "Master" outlet shuts down.

My inner electronic/electrical illiterate is hoping that it might
be a simple as disconnecting a couple of wires in there and
re-connecting them to a different place.

Anybody?
--
PeteCresswell

Hacking APC UPS's "Master/Controlled" Feature?
 

The specs for this discontinued product state that the five outlets across
the top are backed up by the battery.

These outlets will run until the battery voltage drops to where it can no
longer power the outlets. At that point, those five outlets will all shut
off. KA-CHOOM!

IF the device has a "master" outlet (I don't see it in the specs or the
photos), the "controlled" outlets turn on and off with the master, either
for convenience, or to save energy. (My audio system is wired this way --
the electronic crossovers turn the power amps on and off.) Once the battery
poops out, /everything/ powered by the battery shuts off. There is no
graceful shutdown.

You're confusing a convenience feature with operation of the device as a
source of backup power. The two (apparently) have absolutely nothing to do
with each other.

http://www.apc.com/resource/include/...0bb&tab=models

Hacking APC UPS's "Master/Controlled" Feature?
 

Per Nelson:
Your understanding of how it should work is the same as the user
guide's:

Idle peripheral devices (printer/scanners, speakers) continue to draw power
when not in use. To conserve power, the Back-UPS uses ³master controlled
outlets². The Master outlet senses when the master device (computer) that is
plugged into the Master outlet is no longer drawing current, and
automatically shuts off power to the Controlled outlets. Pressing the MASTER
ENABLE button for one second enables and disables this feature. When enabled,

the green MASTER ENABLE LED is lit (on). When it is disabled, the LED is not
lit (off). The Back-UPS ships with MASTER ENABLE activated. Note: Do not
connect peripherals to the Controlled Outlets if you want them to continue to

run when your computer is turned off.

Perhaps you have inadvertently disabled it? Did you try pushing the
button as mentioned?

The lawyers or some other clever souls added weasel words in the
User's Guide | 2 Connect Equipment | Master/Controlled Outlets |
"Note: Do not connect peripherals to the Controlled Outlets if
you want them to continue to run when your computer is turned
off."

For the life of my I can't imagine why they would inflict such a
flawed implementation on their customers. I mean... this is an
Uninterruptible Power Supply, not a friggin power strip... it's
all *about* function when the power fails.

The least they could have done is put that little disclaimer on
the outside of the box.
--
PeteCresswell

Hacking APC UPS's "Master/Controlled" Feature?
 

Per (PeteCresswell):
The lawyers or some other clever souls added weasel words in the
User's Guide | 2 Connect Equipment | Master/Controlled Outlets |
"Note: Do not connect peripherals to the Controlled Outlets if
you want them to continue to run when your computer is turned
off."

For the life of my I can't imagine why they would inflict such a
flawed implementation on their customers. I mean... this is an
Uninterruptible Power Supply, not a friggin power strip... it's
all *about* function when the power fails.

Sorry.... that was a non-sequitur..... I'm so ****ed off over
this that I'm not even thinking clearly any more.

But, to answer your question, yes - I have the feature enabled.

It's just that it does not work when the user needs it the most:
when the power fails.
--
PeteCresswell

Hacking APC UPS's "Master/Controlled" Feature?
 

Per Nelson:

I don't understand what you want. Do you want the "controlled" outlets
to continue to have power after the computer shuts down? There are
other outlets that operate independent of the "master" which do that.
As I understand it the idea behind the "controlled" outlets is that a
peripheral which is only used by the computer, eg a printer, doesn't
need power if the computer is down, so to conserve the remaining
battery power for the useful items, these are shut down in synchrony
with the computer.

I want the "controlled" outlets to be controlled by the "master"
outlet - at all times, as I think most people would impute from
what it says on the box the power supply comes in - not just when
there is external power.

The reason: if the power goes out, I still want connectivity
across the LAN, but I don't want the UPS' battery tb drained
(which shortens it's life).

Sequence Of Events:
----------------------------------------------------------------
- Power fails

- UPS keeps supplying power to PC connected to "Master" and to
devices connected to "Controlled"

- UPS sends message to PC telling it that we're on battery backup

- PC keeps on truckin'.... with LAN connectivity still intact

- PC's Power Management utility kicks in and, after a preset time
or a preset remaining battery life, commences a graceful
shutdown of the PC

- PC shuts down.

- UPS then shuts down the router, switches, and whatever else is
plugged into "Controlled" outlets.

- The UPS battery does not get totally drained.
----------------------------------------------------------------

Maybe I'm the only one.... But this seems so obvious that I just
can't imagine any other implementation in the context of an
Uninterruptible Power Supply.

The power-saving thing sounds nice, but I go back to the fact
that this is an Uninterruptible Power Supply, and not just a
power strip.


I have one of these and it works just fine. There are "uncontrolled"
outlets which are supplied with power whether the computer is up or
down, "controlled" outlets which are only supplied with power when the
computer is up,

This may sound like nit picking.... but it's not quite true that
they are only supplied with power when the computer is up. What's
true is that they are only supplied with power when the computer
is up *and* there is external power.

and surge protected only outlets which are not supplied
with backup power. I would have chosen the mix between these
differently, but that is easy enough to get around by plugging power
strips into one or the other types of outlets.

In my set up, I have the external hard drives and printer connected to
the "slave" outlets and the cable modem and VOIP modem connected to the
"always up" outlets.

When the battery is down to 25%, the computer
shuts itself down along with the peripherals and the modem and router
continue to provide telephone service. Isn't that the same thing you
want?

Where are they getting power, if not from the UPS?
--
PeteCresswell

Hacking APC UPS's "Master/Controlled" Feature?
 

"(PeteCresswell)" wrote:

I want the "controlled" outlets to be controlled by the "master"
outlet - at all times, as I think most people would impute from
what it says on the box the power supply comes in - not just when
there is external power.

The reason: if the power goes out, I still want connectivity
across the LAN, but I don't want the UPS' battery tb drained
(which shortens it's life).

Sequence Of Events:
----------------------------------------------------------------
- Power fails

- UPS keeps supplying power to PC connected to "Master" and to
devices connected to "Controlled"

- UPS sends message to PC telling it that we're on battery backup

- PC keeps on truckin'.... with LAN connectivity still intact

- PC's Power Management utility kicks in and, after a preset time
or a preset remaining battery life, commences a graceful
shutdown of the PC

- PC shuts down.

- UPS then shuts down the router, switches, and whatever else is
plugged into "Controlled" outlets.

- The UPS battery does not get totally drained.
----------------------------------------------------------------

Maybe I'm the only one.... But this seems so obvious that I just
can't imagine any other implementation in the context of an
Uninterruptible Power Supply.

The power-saving thing sounds nice, but I go back to the fact
that this is an Uninterruptible Power Supply, and not just a
power strip.


This may sound like nit picking.... but it's not quite true that
they are only supplied with power when the computer is up. What's
true is that they are only supplied with power when the computer
is up *and* there is external power.


Where are they getting power, if not from the UPS?

And would you want your laser printer to keep running from the
battery? The design seem sensible to me.

Jerry

Hacking APC UPS's "Master/Controlled" Feature?
 

Per Jerry Peters:
And would you want your laser printer to keep running from the
battery? The design seem sensible to me.

No - so I would plug it into one of the uncontrolled outlets.

??
--
PeteCresswell

Hacking APC UPS's "Master/Controlled" Feature?
 

Per (PeteCresswell):
No - so I would plug it into one of the *uncontrolled* outlets.

Oops.... "uncontrolled" SHB "surge-only"
--
PeteCresswell

Hacking APC UPS's "Master/Controlled" Feature?
 

Per Nelson:
I find it a good little UPS for the money. I bought it to get through
short duration outages and it does a good job of it. I don't find the
lack of computer controlled, back up power outlets to be that much of
an issue, certainly at this price point. Not worth getting upset over
anyway :-)

Agreed - I just have this tendency to go ballistic when I see
(according to me.... -) especially-egregious violations of
common sense.

The thing about avoiding the router/switches draining the UPS
battery seems to me tb totally basic to the power loss situation.

I'd been using one of these guys http://tinyurl.com/6ce4f2a with
a conventional UPS and I guess I'll try to find a couple more.



--
PeteCresswell

Hacking APC UPS's "Master/Controlled" Feature?
 

Per (PeteCresswell):
I'd been using one of these guys http://tinyurl.com/6ce4f2a with
a conventional UPS and I guess I'll try to find a couple more.

Or one of these: http://tinyurl.com/3bp3myu
--
PeteCresswell

Hacking APC UPS's "Master/Controlled" Feature?
 

Per Nelson:
You must have really ****ty power if you worried about draining the
battery. My outages are generally not long enough to cause the
computer to shut down much less discharge the battery completely. I
doubt if completely discharging the battery once or twice over it's
lifetime will have much of an impact.

Our outages are rare (as in 1-2x per year max) but when they
happen they can be a day or two. The one we just had was a
couple hours short of two days for us, about 4 days for the guys
across the street.

Within those outages, of course, are many mini or micro outages
where some high-startup-current device kicks in and the lights
dim for long enough to trip a UPS. But in those cases my concerns
are moot.

I don't know enough about batteries to have an authoritative
opinion, but what I've always heard is that total discharge
damages lead-acid batteries from the get-go. I'm pretty sure
I've cooked a couple of batteries on my automobiles by totally
discharging them two or three times. I think that is what's
behind the special "Deep Cycle" marine batteries: they're
specially made so that deep or total discharge will not harm them
as much.

But, to address what I perceive is the real issue: yes, I might
be over-thinking this and yes, it's much more theoretical than
practical.... but that's just my inner obsessive.... -)

--
PeteCresswell