Davbran

I am an estimator working on a conceptual design a need to determine what size temporary power I will need..... inclusive of tower cranes, hoist's, concrete pumps, fire pumps and welders not to mention normal temp lighting and power.....30 to 40 story tower

Looking for advise from experienced electricians with same

John Valdes

I don't think this is a question that is easily answered. You need a list of all the loads for the temp and do a load calculation. Thats the best I can do.

Davbran

I agree and TY BTW.....

I am proposing a 480V 3ph temp and calculating with qualifications of this conceptual design for example

400A load ea for tower cranes

looking for previous experience EC's for loads on items like:

Tower lifts
Demand factor on say 25 welderd
Concrete pump
Fire Pump

This is a conceptual proposal just not experienced with bidding this time of construction. $ value is not the concern my experience is more in site construction multi million dollar project not high rise. TY Neway

nick

Well last year we did a 35 story high rise here in downtown orlando florida 55 West we had a tempower 4000 amp service 480/277 v 3 phase 1st floor on the 14 th floor we had a 800 amp and on the 27 th floor we had a 800 amp each 3 phase 480 /277 v , at each main 800 amp level a transformer step down was used to 120 /208 volts 3 phase . We had a plug and lock cord temp panels turtles on all floors east &west , factory made by hubbell and all lighting temp was floresent fixtures the two tower cranes were 400 amp each . no electric welders used and the buck hoist total of two east and west were 200 amps each . the concrete pumps are nothing there just a pump 480 volts 3 phase 30 amps they are small potatoes and rise up as the floors rise up , there is no fire pump on high rise construction during construction the temp main fire riser just gos up on each level but its just the pressure of the citys force main supply no fire pump needed. this is what we did best to yas

william1978

I would go with what Nick said.


What are all the other Elec. contractors bidding for temp power so that everyone is comparing apples to apples?

nick

[quote=william1978;I would go with what Nick said.


What are all the other Elec. contractors bidding for temp power so that everyone is comparing apples to apples?[/quote]
Well as a electrician i just install the distribution iam not the EC or the estimator , but that is what we put in for our temp power, its common practice we look at all the loads at face value and design our temp to handle it . Nothing special take all the loads an treat it just like a commercial job as the nec code book lays out for us electricians total kw ect ect ect derate if needed as a real job or install what we did may or may not be your scope but it sounded pretty close to me . comments if ya need more help just ask ? look at the service as a real service? best to yas

Davbran

Nick,

Thank you that is exactly the kind of information I was looking for, and know I will NOT hold you to it, it just helps confirm some of my own thought's. This is my first experience here at this sight wont be the last.

Just nice to know there is somewhere out here we ALL can turn to for info like this. Hopefully I can repay the favor one day.

As far as the apples to apples comment, would be nice to see that somewhere in the world today, however for all you estimaters out there when was the last time you saw that......unfortunatly Not the world we live in.....seems most GC's would rather hold a sub's feet over the fire and make him eat it.......As most sub's sign and dont REALLY review thier sub-contract's......in which it clarly state's that you will build according to ALL contract documentation......so unless your fortunate enough to have you inclusions, exclusions scope legally attached as an appendix to the contract guess what.......have fun eating apples.....seriously though I have been reviewing VEry unscrupulous contracts for many years , becomes a big part of front end of most projects.

Have a great day.