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Using the 940-1524 Smart Signaling Cable and UPS Interface Extension Cables

Issue

Using the 940-1524 Smart Signaling Cable and UPS Interface Extension Cables

Product Line

UPS Interface Cables
- 940-0024 Smart Signaling Cable
- AP9825 Isolated Extension Cable

Environment

Enviromments where cable lengths beyond 15ft are required
UPS models that utilize 940-0024 cable and have a DB-9 style serial port

Cause

The 940-1524 cable is included with all rack-mounted and T (208VAC) versions of Smart-UPS with the prefix SU, SUA, SURT, SURTA, and SUM. It is a 15 feet long Smart signaling cable and it replaces the standard 940-0024 cable in rack mount applications, without the need of an additional 940-1500 extension cable to achieve longer lengths. The 940-1524 is not an extension cable. For any application other than rack mount, a single 940-1500 cable should be used in conjunction with a 940-0024. In rare cases, and only in rack environments, it is permissible to use a single 940-1500 with a 940-1524.

The 15 foot black smart cable (940-1524) ships only in rack mount units and has also been included in some other products (SU1400XLTNET, SU2200XLTNET, SU3000TNET, SU5000T, SUA1000RM2U, SUA1500RM2U, SUA750RM1U). It was designed to be long enough to allow a UPS to be installed in the bottom of a rack with the server running PowerChute Plus/PowerChute Business Edition automatic shutdown software installed at the top of the rack or in another rack.

Resolution

APC by Schneider Electric discourages the use of long serial cables due to the potential for signal attenuation and inter-system ground noise. In racks however, these problems are minimized by proper grounding and the fact that the straight line distance between the server and the UPS is usually only a few feet. Because these same favorable traits are not typically present outside the rack environment, the 940-1524 cable is not included in tower (standard) units (except in the 208V models listed above).

In non-rack situations, a standard 2 meter cable (e.g. 940-0024) and a single 940-1500 cable should be used. The 940-1500 cable (available as AP9815) provides superior shielding, better insulation, heavier conductors and more noise filtering circuitry than our standard cables to ensure minimal attenuation and noise interference. In rare situations, and then only in rack environments, does APC recommend that you use a single 940-1500 in conjunction with a 940-1524.

The Network Enhancements division has developed an Isolated Extension Cable (IEC), APC part number AP9825 which converts serial RS-232 signaling and places it on category 5 twisted pair wiring, thus allowing up to 100 meters (328 ft.) of total cable length. The AP9825 can be purchased through APC by Schneider Electric or through your APC by Schneider Electric reseller.