Why do some people advise you not to use a UPS unit with a cable modem?

Posted on 2006-04-20
Last Modified: 2013-11-30

A UPS evens out highs and lows, and maintains power (for a while) during outages.

It seems to me that it would be a good practice to plug your cable modem, router, firewall etc into a UPS unit if you have one available with sufficient capacity.

But some people say not to have the cable modem on the UPS.

What would be the reason for this?
Question by:Tomster2
    LVL 5

    Assisted Solution

    I have never heard of that. I always plug in users cable modem and routers to the UPS. It's the monitor which you want to avoid.
    LVL 77

    Assisted Solution

    by:Rob Williams
    Can't imagine why you wouldn't want to have the cable modem on a UPS. As you mentioned, the only concern I could see is, does the UPS have sufficient power to support all devices. As a rule we always put modems, routers and such on a UPS, but we do use a separate unit. Some rural locations have "dirty" power which results in brown outs and Internet disconnects, the UPS evens that out an maintains connections.
    Just my thoughts.
    LVL 13

    Accepted Solution

    I don't know for sure; I've heard no valid reason not to, and there are plenty of reasons to use an UPS for your cable modem/router/etc:

    Protect your device's ac adapter from surges
    Protect your device from power drops, which can result in configuration loss (dhcp on some models, firewall settings, pinholes, MAC address settings, etc).

    I wouldn't worry about it. Unless your modem manufacturer specifically says not to, there are plenty of advantages and no disadvantages to putting your device on an UPS. Of course, make sure the UPS can handle the load of the device, your PC, and monitor.

    Now printers are another matter; you should never put a printer on an UPS since they draw so much power (particularly laser printers). Make sure they are on the Surge Only side or on a separate surge protector. But a cable modem or router should be fine.
    LVL 77

    Expert Comment

    by:Rob Williams
    Thanks Tomster2 ,

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