Maker Pro
Maker Pro

2 Portable generators

Nb778

Jun 24, 2017
5
Joined
Jun 24, 2017
Messages
5
I always used 2 generators when I used different cables to connect one to my home appliances, lights and a clean inverter type for my home office computers, printers, router, telephones.

Well, I decided to use an interlock in my main breaker box so now my main 5KW generator is wired into my main house breaker. Everything works well, but my computer UPS's are clicking every time a printer goes on, or during surges.

So I am thinking of doing the following:

All my pc's are connected to UPS. Same goes for my cable box and my phone box. So what if I connect the inverter generator as I did in the past, to all these U PS units?

None will be plugged to the house AC.

The only common connection is the ground connection to the house water pipe of my tv/internet cable and phone systems.

Can anyone think of a potential issue here?
 

Externet

Aug 24, 2009
891
Joined
Aug 24, 2009
Messages
891
Never use an UPS for printers. Only for the CPU, that is what you want to protect from outages and perhaps monitor in order to shut down properly.
 

Nb778

Jun 24, 2017
5
Joined
Jun 24, 2017
Messages
5
Thanks for the reply. The printer is connected to the surge protector (not the battery side).

I can not think of any issue doing this, but my electrician said he does not like to have more than one generator. I explained to him that there will be no connection between the regular 5 KW generator which feeds the entire house and the 2.4 KW inverter generator I like to use for the home office computers.

Thinking more about it, the only devices which will be connected to both generators will be the cable boxes since I have 1 in the home office and 2 in the kid's rooms. So one cable box and tv will be connected to the inverter and the other 2 to the main generator.

Is that a potential issue?

And as I mentioned above, the cable and FIOS case grounds are grounded to the water pipe.
 

Externet

Aug 24, 2009
891
Joined
Aug 24, 2009
Messages
891
Hmmm... Are the neutrals of both generators joined together to the house neutral ? Is there a possibility the neutral used for the computers reaches path -say internally to the printer , or UPS- into a wall outlet ?

I would start disconnecting things one by one until the misbehavior stops. -Process of elimination-
 

Nb778

Jun 24, 2017
5
Joined
Jun 24, 2017
Messages
5
I have not tried to do this yet.

There are no common 120 V connections (neutral or hot) between the 2 generators. The 2 neutrals are not connected together. The inverter generator will connect the 120 V single phase output to multiple UPS. The UPS's will not get plugged in the wall. They will all plug into the inverter generator.

The UPS will then power up 3 pc's, one printer, a cable modem/router/switch and the FIOS phone router.

So the only connection which is common between the 2 generators will be the case ground going to the water pipe. Since this is not a current carrying path, I can not see a potential issue here.

Even though the 2 set-ups will be completely independent as far as 120 VAC is concerned, there will be cable coax cables connecting the cable boxes, modem, TVs. Those are the only connections which will be indirectly connected to the 2 generators. So one cable box will get 120 Volts from the main generator, while another cable box will get 120V from the inverter. There are 2 RF splitters used to route the single cable input to multiple cable boxes.

So I guess the question comes down to:
Are the cable RF/Video/Audio coax input/output connections in any way connected to the AC input voltage? That is the only path I can see becoming a potential issue.

Also, CAT5 cables from the routers will be going to devices powered by both generators.
 
Last edited:

BobK

Jan 5, 2010
7,682
Joined
Jan 5, 2010
Messages
7,682
You do realize that the neutral and ground wires are connected together at the distribution panel.

Bob
 

Nb778

Jun 24, 2017
5
Joined
Jun 24, 2017
Messages
5
Yes the GND and NEU are connected at the main outside panel. Then there is a sub-panel inside the house where the GND and NEU split of course.

The cable boxes do not have grounded plugs, but the RF coax shield is at GND potential when I measure the AC voltage at the plug relative to it. Is it getting the ground from initial connection outside the house going to the water pipe? or is the cable box case tied to NEU?
 

flyboydale54

May 25, 2010
1
Joined
May 25, 2010
Messages
1
Printers make electrical noise.

I have seen a lot of people plugging their Printer into the same power strip as their PC and Monitor. When the printer is used, noise is transferred down to every device plugged into that power strip. This can cause the digital logic in a computer to be changed from a 0 to a 1, or a 1 to a 0. This is a major cause of computer errors and corrupted data.

This is what I use to isolate my printer from my PC and their devices such as the monitor, etc. How do I isolate? Simple, I use a Tripp Lite ISOBAR unit. I prefer to buy the ones with 8 plugs on it. Each set of plugs looking like your wall outlet above and below each other are physically connected together. However, each pair of plugs above and below each other are isolated from each one next to each other. With that in mind, you have 4 isloated pairs of recepticles next to each other with an 8 recepticle unit. Each one of these sets are not physically connected to each other. They use very large Torrid Coils to induce the current between each pair above and below each other to each pair beside each other. There is also very large Metal Oxide Varistors inside them to protect your equipment from Voltage Surges.

With this in mind, imagine plugging the printer into the last set of recepticles furthest from the power cord of the protector unit. Then plug a plastic protector into the recepticle below where you plug the printer in. That is so you do not plug anything into the physically connected (wired) recepticle the printer is plugged into. Now, plug your PC into the first set of recepticles above/below each other, your monitor beside those, and presto, it leaves another spare which I use to plug both my router and modem into, using the recepticles above and below each other.

You do not need to isolate the modem and the router from each other. There, presto, your printer and every other device is isolated from each other. End of noise, end of problems caused from printers which are big electrical noise makers.

Now, plug the unit into your UPS and I bet your UPS will no longer click, click, click, when the printer is being used.

If you want phone line protection, then buy the unit which has the added phone protection ports.

Any electronic device plugged into the unit is covered by a several thousand dollar warranty protection from any damage due to a voltage surge. Even from a direct hit by lightning, your equipment is covered.

Just remember never to plug any device below the recepticle where the printer is plugged in!


[MOD NOTE: www link and a few references to the mentioned unit removed]
 
Last edited by a moderator:
Top