Unitized Distribution Substation (UDS) Installed Cost Comparison
This document is a detailed economic comparison between the installed cost of VTI's Unitized Distribution Substation (UDS) and a system using separately mounted components for a typical 120 Volt lighting distribution system. This comparison study is based on the requirement for a 45 KVA, TP-1 Energy Efficient, 480 Volt to 120/208 Volt 3 phase transformer, a secondary main breaker, a 3 phase 4 wire 225 Amp panelboard and 42 - 1 pole, 20 Amp branch circuit breakers.
Installed Cost of VTI's UDS
VTI's UDS selected for this study is catalog number UDS MB45-3480-42 with 42 - 1 pole, 20 Amp plug-on branch circuit breakers.
UDS Cabinet Cost: $6,859.00
Field Labor Cost: $171.04
TOTAL INSTALLED COST OF VTI's UDS: $7,030.04
Installed cost of system using separately mounted components
For this study we used the following Bill of Materials and field labor estimates:
Installation Cost Consideration:
According to field electrician reports, connecting the branch circuits on a panelboard with a 4.5"D x 5"W wire gutter takes about twice as long to make as in the UDS where you have 9.75"D x 9.5"W wire gutter.
So with 126 connections to make (42 - 2 wire circuits plus ground), you have this additional cost to take into consideration:
0.10 hour per circuit connection: 12.60 hours at $51.83/hr: $653.06
Subtotal Installed Cost: $6,842.82
Purchasing: Procurement of 27 line items vs. one item for the UDS.
Additional time: 1.20 hours x $70.00/hr. = $175.00
Design: One item to specify and locate on drawings or wiring diagrams vs. multiple items with breaker, wire and conduit sizes to be specified on drawings. Field takeoff for 27 line items.
Additional time: 3.50 hours x $75.00/hr. = $262.50
Material Handling: Receiving and storing material on job site; one item verses 27 items.
Additional time: 2.0 hours x $35.00/hr. = $70.00
Material Damage and/or Loss: Loss and/or damage of small parts, wire and hardware.
Industry average: 1.85% of $4,824.24 = $89.24
TOTAL INSTALLED COST OF SEPARATELY MOUNTED COMPONENT SYSTEM: $7,439.56
One of the major benefits realized when using the UDS cabinet is its physical space savings. Comparing the physical space required, as seen in Figure 1, and by equating the differences to building costs, the dollar savings becomes significant when using the UDS cabinet. This additional space savings of $2,248.40 is calculated by using average pricing for floor and wall space in a typical ECR.
Therefore, the potential overall savings realized when using VTI's UDS is $2,658.00 which is the cumulative result of the $2,248.00 savings in physical space and the $410 savings in installation cost.
Note: These prices and times are based on extensive feedback information obtained from third party users. Your actual costs and field labor estimates may be different. However, in any evaluation it would be difficult to see that these differences would offset the overall total savings presented in this study.
TOTAL POTENTIAL SAVINGS when using VTI's UDS is $2,658.00