Re: Cascading UPSs

On 1/7/2025 4:27 AM, Sylvia Else wrote:

On 07-Jan-25 5:22 am, Don Y wrote:

OTOH,  I *could* plug more than one UPS into a single (or few)
"master" UPS that effectively takes on the role of the mains
connection.  Then, I just have to keep that/those UPS running
("properly") to gain the benefits of bridging those brief glitches.
>
Any downsides to this?  If I remove the batteries from the
"slave" UPSs (i.e., don't replace them when they fail), then
I can avoid that maintenance issue but still retain the other
advantages of the UPS-per-workstation.
>
Or, maybe put some trivial "power source" in their place that
is just enough to satisfy the UPSs' expectations of a "battery"?

 Some UPS designs cannot be turned on[*] without a battery in them, even when supplied with mains power, because they cannot energise the relay that enables the mains connection.

Hmmm... I've found devices that can't be powered on in the absence of
MAINS voltage (which, IMO, is an annoyingly arbitrary constraint...
suitable for discard).  But, all seem to power on without a battery
(assuming mains voltage is available) though may "complain" about the
fact.
These have the annoying habit of persistently displaying "Connect Battery"
message -- which can't be dismissed (in favor of the other status messages).

[*] They can stay on, just not be turned on.