I'm working on the design of a service for lights at a ball field. The poles are concrete and will be 70ft above ground level. The pole has a bare Cu. wire encased in the concrete and bonded to the lights supports. My questions are:
1. Should I terminate the bare Cu. wire at the bottom of the...
Hello there, our company has to provide test results on the Thermal Resistivity of a concrete mix design for a duct bank. Does any one know of a testing company that can do this type of testing and is located in the state of Florida?
Thank you.
Chapter 430, Part X of NEC requires that feeders for VFD be rated at 125% of their rated input. I would like to know if I'm interpreting this correctly. If I have a VFD rated at 400A, the feeder for this VFD will have to be sized for 500A (400*1.25)? Ahead of the VFD, the feeder for the motor...
Hello, I have a question on using the foundation rebar as one of the grounding electrodes. The code specify the use of a concrete-encased electrode when the concrete foundation is in direct contact with earth and other restrictions which are not in question.
Should this method be suitable when...
Hy everybody,
I'm thinking on open a consulting firm and hopufully somebody can answer some questions.
Are the engineering fees different from the drafting fees?, when the company offer both services., or are the drafting fees included on the engineering fees?
Regards
Hi, may be I'm missing something. Sometimes when I asked for the electrical specifications/requirements on an HVAC unit condensing/AHU, the people give me the tons. Like 4 tons 15 tons. Is there any way that you can size the min/max protection on these units just having the capacity in tons...
Hello, I'm planning on buy a software to perform Coordination Studies, Short Circuit, Power Flow, Arc Flash and possible Harmonics. Could you people give me some advice between ETAP and ESA, pros versus cons. Which may be the best way to go getting the more practical uses of the software...
Hello there, we are discussing the use of GFI receptacles in commercial bathrooms and there are different arguments, I hope you people share your knowledge. Here are the issues, It is required in a commercial bathroom (one toilet one basin) to install a power receptacle? and if is required it...
Hi there, I was asked to check an existing building. The building has a restaurant and a retail area and the intention is to renovate the retail area. I don't have any drawings yet on the existing conditions, the owner is working on that.
There are two gas operated water heaters inside the...
Hy, we are installing a transformer 69/12.47 kV , 30/56 MVA. The actual design for the secondary conductors is 2- 1750 bare Cu./phase. 1.Has any body knows the availability of this type of conductor?
2. There are some concerns with the weight that will be imposed to the bushings. Any...
Hello, can a panelboard be installed 20" from a drinking fountain, as long as you have the 30" working space in front of the panel? or do I need to treat it as a receptacle next to water, so that the working space be at least 6' from the drinking fountain? (I probably don't want a GFI panelboard...)
Hello, I'm working on making a simple program to perform Power System Analysis. This will be for my personal use. I have the calculations on Excel and have some Macros on Visual Basic. I would like to create graphics for the elements (i.e. Cables, Loads, Transformers) and assign/adjust the...
Hi, can anybody tell me where I can find the minimum illumination requirements for listed ocupancies. I'm specifically looking for a hair salon. The clients may want that the barber be able to distinguish between their hair and their ears.
Hi everybody, I'm working on the calculations for a strip mall consisting of 10 tenant spaces. 2-10kVA Heating units for two spaces and 8-8kVA Heating units for the remaider spaces. Cooling load is less than Heating, so only the heating load is considered. Is there any rules that allow...
We are going to install a new sports lights system on an existing ballfield. The existing A/C Panel is a 480, 3ph, 225A. The new load is 160A and after appling the continuous operation factor is 200A (160*1.25).
1. Can I use the existing A/C Panel?
2. It is right that the breakers can be loaded...
