Clarifications_4-27-15.pdf

4/23/2015 IFBP04131500001

REWORK ELECTRICAL DISTRIBUTION

FCI SANDSTONE, MINNESOTA

CLARIFICATIONS

QUESTION: Are the existing transformers the same size as the new ones 300kva?

BOP RESPONSE: Yes.

QUESTION: If the existing transformers are 300kva then the following statement made in the specs are not need to be addressed – spec section 26-12-00 1.4 B. states “Provide calculations for determining KVA ratings of new transformers provided” need clarification?

BOP RESPONSE: New transformers will be 300kva and the secondary conductors need to be sized to accommodate the load.

QUESTION: Section 26-12-00 1.5A requests spare fuses but I do not see any fuses requested as part of this project. I also do not see any other work beyond the replacement of the transformers and they do not seem to indicate that they will come with primary or secondary protection; need clarification?

BOP RESPONSE: Primary protection will be required as well as secondary. Please see amendment 0005 posted on 4/23/2015.

QUESTION: On the drawing it shows US4 being moved outside of the building from the basement. How does the Government want the new transformer be fed i.e., above ground, aerial, or direct burial through basement wall; need clarification?

BOP RESPONSE: Direct bury, RMC encased concrete.

QUESTION: Testing according to the spec requested in 26-12-00 3.1A? has to be done independent NETA testing contractor. Can all of the transformers be tested once they arrive at the facility and before they are installed; need clarification?

BOP RESPONSE: Need to be tested before primary voltage is applied.

QUESTION: Will a new concrete pad for the new transformer be required, as well as new underground, concrete encased conduit system for both the primary and secondary conductors?

BOP RESPONSE: A new pad will be required for the new transformer, also new underground. Primary conductors need to be ran in rigid conduit encased in at least 4” of concrete.

QUESTION: Are the existing primary and secondary conductors to be removed from their present location and the floor repaired as necessary?

BOP RESPONSE: The primary conductors will need to be removed.

Secondary conductors may need to be terminated in a cabinet or extended to new gear either inside or outside.

QUESTION: If so, what size and how many secondary conduits/conductors are required, and what is the distance from the new transformer to the secondary switchgear?

BOP RESPONSE: There are five 4” RMC’s, two 3” RMC’s, one 2 ½” RMC, and one 1” RMC. The conductor sizes vary from #8AWG to 250Kcmil CU and some are parallel runs. Distance from existing to new is approximately 100’.

QUESTION: IS GRC (galvanized rigid conduit) the required raceway means?

BOP RESPONSE: Galvanized rigid conduit is the required raceway means.

QUESTION: Specification 2.1 F, “Delete all references to liquid immersed Bayonet Fuses,” our supplier wants to know how you will protect the transformer without fuses?

BOP RESPONSE: The transformer will be liquid immersed bayonet fuses. Please see Amendment 0005 posted to FBO.gov on 4/23/2015.

QUESTION: Are the transformers radial or loop fed?

BOP RESPONSE: We have a combination of both radial and loop fed transformers.

QUESTION: Live or dead front?

BOP RESPONSE: Dead front.

QUESTION: Would it be possible to provide any pictures of the installations, in particular, the existing location of US4 and its new planned location?

BOP RESPONSE: Pictures not available.

QUESTION: Can you please provide the existing transformers manufacturer, type, model, connection type/label information/pictures.

BOP RESPONSE: T-7, T-8, and T-9 are SilPac Power Supply Pemco Corp, Type - In Model #PMN-300, Eyelet to dry fuses primary with a lug secondary, T-12 is a Square D Type - Oil bath fuses Non pcb Model #V73A515 TF4, Load break 90's with a lug secondary, US-4 is a Square D Type SHT air/fan cooled Model #152-525, Eyelet Primary with a lug secondary and a Mail Distribution Panel attached.