David CM Weber wrote: > Do you have any hard evidence (e.g.: manufacturer warnings) > on the dangers of surge protectors & UPS'. I've never heard it > before, and the people w/ EE backgrounds in the office seem > skeptical.
and: > The phone system is hung off of a UPS (not overloaded). [...] > CO lines are plugged into one of those powermax ( I think) CO > line & powerstrip combinations. In addition, the powerstrip is > then plugged into the UPS. BTW, the ups is a typical APC job. Tom Curbishley wrote: > If the "power strip" is actually a surge protector, don't plug it into > the UPS. The surge protector could fry your UPS while operating > on battery. As an APC and Panamax dealer this is an issue we have actually dealt with before. The APC units provide very good protection from surges and spikes, so little is gained by placing a surge protector after the UPS. In fact, placing a surge suppressor after the UPS can be a problem. When on-battery most UPS units output a "stepped approximation" of a sine wave. Surge suppressors are designed to operate on a true sine wave from the power company and will see the stepped approximated sine wave as a spike. The resulting constant activation of the surge suppressor's protective circuitry can overload the UPS. Even though the APC units will disconnect their output in this overload condition, they could possibly be damaged. Therefore, we always put the surge protection before any UPS equipment. The Panamax units are great for providing complete protection on all incoming paths to the equipment (e.g. A/C and CO lines). It is critical that the same ground reference is used when protecting the KSU and related equipment, so we often use the Panamax TowerMax products [BTW, Panamax recently sold this line to ITW Linx]. With the UPS after the surge protection, the surge suppressor acts as a first line of defense against any power problems to all the equipment and the UPS serves only as the backup power supply. If additional outlets are needed off the UPS we use a basic power strip that has no surge protection circuitry. Here's an excerpt from a technical note we have from APC... "APC recommends against the use of any surge protector or power strip being plugged into the output of an APC Back-UPS or PowerCell UPS**. Doing so, could result in your load being rebooted or dropped during a power failure and, therefore, could void your warranty and Equipment Protection Policy (EPP). Plugging a surge strip into the output of these UPSs could capacitively overload the UPS due to its Stepped Approximated output waveform on battery causing damage to the internal circuitry of these models. ** The use of an APC Surge Arrest or Surge Station product plugged into the output of the Back-UPS Pro and Back-UPS Office family of UPSs is permitted. In these cases, your warranty and Equipment Protection Policy is maintained." I find it interesting that their SurgeArrest and SurgeStation products are designed to work with the UPS output, but I do not know what is different about the design of these products to allow this. It is not something we have ever found the need for. Hope this helps. Ian Goldstein TEKTREVE SYSTEMS Tel: 631-912-2620 Fax: 631-912-2625 _________________________________________________________________ KX-T Mailing list --- http://kxthelp.com/ Subscription changes: http://kxthelp.com/mailman/listinfo/kxt
