#CUMMINS POWER SUITE SOFTWARE SOFTWARE#
#CUMMINS POWER SUITE SOFTWARE CODE#

The NEC provides language in informational notes regarding voltage drop criteria for branch circuits and feeders to provide reasonable efficiency of operation. Voltage drop: Voltage drop is an often overlooked requirement for electrical systems. For this scenario, a second run of conductors is implemented to form an additional parallel run of conductors in the duct bank to accommodate the considerable cable current-carrying capacity reduction due to burial depth. For a similar duct bank at 19 ft deep, the AmpCalc result was 225 A, a 24% reduction of current carrying capacity from the NEC value based solely on burial depth. For example, for a 500 MCM 5 kV cable, NEC Table 310.60(C)(78) lists 295 A for three aluminum conductors in a 27 in. As discussed, the tables in NEC Article 310.60(C)(77) through (80) list ampacities for burial depths of up to 30 in. This scenario has a worst-case burial depth of 19 ft as it enters the building and traverses through some site grade elevation changes. The program uses the Neher-McGrath calculation procedure to determine underground cable temperatures or cable ampacity ratings for virtually any duct bank or direct burial cable configuration.Īt Project X, a concrete-encased medium-voltage duct bank is designed to enter the building and snake under some water pipes, and enter the electrical room just above a structural footing. It is the engineer’s responsibility to determine if a load factor less than 1.0 is appropriate for the cable design.

The load factor is the average load in kW supplied during a designated period divided by the peak load in kW taking place in that period. The load factor is another major component to the calculation. A conservative value of 90 RHO should be used if actual data are not available. Therefore, the cable ampacity is optimized. Lower RHO values indicate a low thermal resistivity. An effort should be made to confirm the RHO value of the soil. For underground systems, the effect of burial depth, type of burial (direct or concrete encased), and soil thermal resistivity (RHO) will determine the cable temperatures and ampacities for a given scenario. The latest version has also added a feature for aerial calculations.

#CUMMINS POWER SUITE SOFTWARE SOFTWARE#

AmpCalc (cable ampacity software for underground systems) from CalcWare Company is a computer program that calculates power cable ampacity ratings and/or cable operating temperatures for user-defined underground cable installations (see Figure 3). These tables provide basic current-carrying limitations of conductors at assumed earth temperatures, and thermal resistances for conductor temperatures of 90 C and 105 C, all at assumed burial depth of 30 in. The NEC does not publish similar ampacity tables for buried low-voltage (0 V to 600 V) conduit.

#CUMMINS POWER SUITE SOFTWARE CODE#

As of the 2011 version, the National Electrical Code (NEC) publishes ampacity tables in Article 310.60 for medium-voltage (2,001 V to 35,000 V) cable installations for a few directly buried cables and several duct bank profiles. The Windows-based software is available online for purchase and download.Ĭable ampacity: For the same service and feeder duct bank sections modeled for cable pulling at Project X, the burial depths of these conductors are continually adjusted due to structural and other utility coordination. is a software tool for performing cable pulling tension calculations and conduit system design. Pull Planner 3000 from American Polywater Corp. It is an Excel-based calculator specific to Southwire products. SIMpull Cable Pull Calculator from Southwire is a convenient online tool for cable pulling calculations and estimating support in a spreadsheet format. It also helps demonstrate that a manhole is not necessary as a pulling point for the duct bank routing from the central utility building and the main electrical room, thus informing the designer so that the proper installation is constructed (see Figure 2). For Project X, the Cable 3D program is used to document sections of the utility service entrance duct bank, and to adjust bends of cable profiles between sections of medium-voltage cable runs. The Cable 3D program provides both forward and reverse pull results for each cable profile modeled. This presents a challenge in terms of cable pulling and determining the proper location for pulling points along the system.įor complex cable pulls or simply to document a cable pull run, the software tool Cable 3D from SKM System Analysis models complex three-dimensional cable-pulling tension and sidewall pressure calculations, allowing rapid and accurate design decisions. The result is a service and feeder duct bank system with many bends, elevation changes, and offsets.

Cable pulling: The site electrical infrastructure distribution for Project X presents existing utility conflicts.

Cummins power suite software