In this case, where does bonding come into place besides the bonding bushing? ]]>

I need help to size a transformer that will be used in a supermarket.

According to my calculations, I get the following kVA:

To get these numbers I start measuring Amps for each item. The formulas are shown below:

kVA(3-Phase) = Volts * Amps * sqrt(3) / 1000

where Volts: 220V (S. America)

The total Power is

What size of transformer do you recommend? Is it better to have 2 transformers with lower capacity or a big one? Will compressors in the system have to be considered for power correction? Thanks in advance for your support!

Details on Power Calculation:

Item |
Qty |
Power/unit |
Power |
1-Phase |
3-Phase |

Microwave | 1 | 12A | 12A | 2.64kVA | |

Fan | 1 | 0.5A | 0.5A | 0.11kVA | |

Ventilation | 1 | 2A | 2A | 0.88kVA | |

Scale Type1 | 4 | 0.3A | 1.2A | 0.264kVA | |

Scale Type2 | 1 | 1.5A | 1.5A | 0.33kVA | |

Hydraulic Press | 1 | 4A | 4A | 0.88kVA | |

PC | 1 | 1A | 1A | 0.22kVA | |

Kitchen Cutter | 1 | 3.5A | 3.5A | 0.77kVA | |

Scale Type3 | 1 | 0.3A | 0.3A | 0.066kVA | |

Packager | 3 | 1.5A | 4.5A | 0.99kVA | |

Meat Grinder | 1 | 2.5A | 2.5A | 0.953kVA | |

Meat Saw | 1 | 1.7A | 1.7A | 0.648kVA | |

Vacuum Packager | 1 | 7.5A | 7.5A | 1.65kVA | |

Checkouts | 18 | 5A | 90A | 19.8kVA | |

Server | 1 | 5A | 5A | 1.1kVA | |

Cooling Equipment | 1 | 400A | 400A | 152.4kVA | |

Water Pump 1 | 1 | 4A | 4A | 1.52kVA | |

Water Pump 2 | 1 | 5A | 5A | 1.9kVA | |

Illumination | 1 | 214.4A | 214.4A | 94.33kVA | |

AC Unit 360k BTU | 5 | 51.4A | 257A | 97.93kVA | |

AC Unit 500k BTU | 1 | 71.4A | 71.4A | 27.2kVA | |

AC Unit 18k BTU | 1 | 9.1A | 2A | ||

Electrical Doors | 2 | 0.8A | 1.6A | 0.35kVA | |

Kitchen Equip 1Ph | 1 | 11.85A | 11.85A | 5.2KVA | |

Kitchen Equip 3Ph | 1 | 362.7A | 362.7A | 138.2kVA | |

SUB TOTAL | 131.74KVA | 420.78kVA | |||

TOTAL |
552.5kVA |

my connected load is 1650KVA.

my total calculated load (with demand factor of 23% 220.84) is 380KVA.

My service conductors need to be rated for 1055A.

Do i need to multiply this by 125% to get my OCPD (1600A)? Or just round up to 1200A??

Thanks! (code sections would be great) ]]>

This is new to MN and myself. I was curious if anyone has control methods that seem to work well for the end users. Please share your experiences.

Thanks, ]]>

Most look like older Westinghouse but all labels are gone and there are no identifiers for model or current ratings. I popped the covers on a few and the internals look to be in good condition.

Is there a way to determine trip rating and Max AIC with no markings on the case? ]]>

the question is resistance of conductors and how to measure it on the job from load center to, say, light pole base 185' away (with ballast leads disconnected). on the job im sure I could play around with my meter and find my answer but if I spent a few hours educating myself it would be followed with the foreman asking "what the heck are you doing?!"

I can use my ammeter and figure out total power and amps easily but id like to know the ohms of 2 wires w/o all the length and diam. formulas.

so...using ohs law, I should be able to measure E & I at the loadcenter and compare at the light pole base (except with the ballast isolated I cant get I) and find resistance. right? or is simply using the multi meter between the conductors what I want?

Im sorry if im over thinking this...thank you for reading. Again,just looking for a quick way to find resistance of two conductors on the job.... ]]>

Who is the AHJ over cars, airplanes and boats?

For instance, someone who will remain nameless used EMT and spot welded it down a piece of iron and used a 4X4X24" 3r wireway which he cut down to 4X4X4 put the end cap on it and ran the emt into the box with no connector. I know this is a violation, but I cannot prove it beyond a shadow of a doubt. Can someone help me explaining this to him. Thank you. ]]>

Is CSA rating for a hazardous environment acceptable in the United States, or does FM have to rate the equipment for the hazardous location in order to install it in the United States? ]]>

I know the transformer will dissipate heat during this time due to losses in the primary winding. I could potentially place a small load across the secondary of the transformer that would amount to around 20VA, and would always be present. Would it be better design to have this small load connected across the secondary of the IC transformer, or would any benefit from this not amount to much? ]]>