RFI__4.pdf

RFI #4

1) 2.1 - Pre-Construction. Contractor to provide engineering drawings (Plus, 4.4.1, 4.4.2 , and 6.3.2 - All

Drawings.). Do any of these drawings require a Maryland PE Stamp? No

2) Section 3.1 - The existing 800amp panel located in building 1110 appears to be loaded up with breakers/circuits.

It appears that the existing 800amp service will NOT handle the additional load of the new modular building. Please provide the existing load calculations on the existing 800amp panel located in building 1110. Based on the electrical panel calculation the draw of the power is 443.2 amps per phase. Using the 80% safety factor, there is 354.5 amps per phase. Remaining power is 445.5 amps of the 800 amp panel.

3) 3.1.1 - States estimated load for new modular building 200amp panel. Note that the new modular load will require a 400amp 3 phase panel. Based on our preliminary calculations the total estimated load is 302 amps.

Spread that across three phases you get roughly 100.66 amps per phase. 80% safety factor allows for 160 amp per phase. We are within the safety range. Contractor should verify this data and provide reason for the requirement of a 400 amp panel.

4) 3.1.2 - States to replace the existing 60amp breaker with a 150amp breaker. A 150amp breaker will not handle the load of the new modular building. It is standard for electric panel build outs to have different size bus that your breakers attach to. It appears that the buss size in the existing 800amp panel is rated for 100amp breakers. Even if a

150amp service was sufficient for the new modular the 150amp breaker will not fit in place of the 60amp breaker.

The panel cover would have to be removed to check the buss out and see if the buss can be modified to accept a larger frame 150amp breaker. The 60 amp panel on site shall be removed. Submit your bid for the existing solution.