Electrical wiring question

[CobyRupert]

They do not have to be located in an air-conditioned space if there is adequate airflow. Ours will be in an unused room in the house that has AC with the door closed. I fully expect it to get hot in there but it shouldn't impact the AC bill too much. I would put the things out in my shop but I am worried about all the welding and grinding dust getting sucked into the fans. On the bright side when winter comes they will offer heat.

Quick math: 12 amps/circuit x 6 circuits x 120V = 8640VA. Lets say 99% of this is heat, that's a heat load of over 8550 Watts (8.5 kilowatts) being dumped into the room, or 29,000 BTU/hr. That's substantial.

 

[buickanddeere]

What is the watts to compare them to the VAR's. the only heat from the reactive power is the I2R losses in the conductors, contacts, power supplies etc.

 

[CobyRupert]

What is the watts to compare them to the VAR's. the only heat from the reactive power is the I2R losses in the conductors, contacts, power supplies etc.

Most people agree, as do I, that pretty much all of the energy that goes into a computer is converted into heat.
How much of a computer's energy goes to heat? - Quora

 

[roadhunter]

A VFD provides a true three phase power with exactly 120 degrees between phases . Applied voltage is also identical phase to phase . Three phase motors driven from a VFD vs a rotary converter can operate at full rated shaft HP without exceeding rated FLA on any phase . The VFD driven motor operates quieter and cooler. The motor starting torque , ramp up speed , stall torque, reversing and instant stop can be programmed . Rpms can be controlled .

In this case my machine has multiple motors all fed with a 40 amp 3 phase service. total of 3 - 1.5 HP motors and a 10 hp motor for the hammermill. There is a VFD on one of the 1.5 HP motors to adjust how fast the chips go into the hammer mill.

The other challenge is that there are chips in the hammer mill during startup which requires extra force to get spinning.

I spoke to several places about my application, a couple of which sold VFD's as well as rotary converters. None steered me toward a VFD. That's why I'm curious why you think a VFD is better for all applications including this.

 

[newbury]

Well "rule of thumb" says 2HP VFD for 1 HP of motor

Thus, the rule of thumb for sizing the single phase input on a three-phase drive is to use a VFD rated for 2 times the FLA of the motor. For example if your motor is a 10 HP motor with a FLA of 28 amps, then you would need to select a VFD with an amp rating of 56 amps which ends up being around 20 HP.Jan 18, 2014
VFD Buying Guide - VFDs.com
VFD Buying Guide

I've got the following 3 phase equipment:
5HP
5HP
3HP
3HP
2HP

None that will be run at the same time (I'm one person)

I've bought (~$100) a 10HP motor and planned on getting a 10 HP CNC-GRADE ROTARY PHASE CONVERTER for $200 so I can wire up my shop for 3 phase.

Are you saying there are VFD's so inexpensive I could dedicate one to each machine? If so where do I find them?

Ebay is one of many sources. Either a VFD for each 3 phase machine . Or Setup one 3 phase inverter to supply a three phase service. Then wire each three phase machine to the service.

So - prices from a quick look on ebay:
5HP needs 10HP vfd $255
5HP needs 10HP vfd $255
3HP needs 6HP vfd $223
3HP needs 6HP vfd $223
2HP needs 4HP vfd $133

So it will cost about $1100 for my solution.

I hadn't looked in a while so I thought maybe you had found a VERY inexpensive source for VFD drives.

It was my understanding that VFD's must be "tuned" for different motors.

 

[buickanddeere]

Well "rule of thumb" says 2HP VFD for 1 HP of motor



So - prices from a quick look on ebay:
5HP needs 10HP vfd $255
5HP needs 10HP vfd $255
3HP needs 6HP vfd $223
3HP needs 6HP vfd $223
2HP needs 4HP vfd $133

So it will cost about $1100 for my solution.

I hadn't looked in a while so I thought maybe you had found a VERY inexpensive source for VFD drives.

It was my understanding that VFD's must be "tuned" for different motors.

one 10HP VFD will run any load one at a time. Each electrical load will have to depend on it's own thermal protection from overloads. Frequency/rpm control, reversing and ramped starting would remain possible with one VFD supplying any of the motor loads.

 

[bdog]

I don't mind at all carry on but it cracks me up. My thread was about how to wire up a breaker box and it has devolved into half the people talking about bitcoin mining and half the people talking about VFDs. I got the panel wired up and running so life is good.

 

[joefromga]

Bitcoin went up nearly 300$ yesterday.

 

[TMGT]

I don't mind at all carry on but it cracks me up. My thread was about how to wire up a breaker box and it has devolved into half the people talking about bitcoin mining and half the people talking about VFDs. I got the panel wired up and running so life is good.

Glad to hear, I was getting worried I missed some question about running 3phase equipment.........

As for computer heat, I use to heat a small unisulated block dorm room with 2 older laptops, this was in Michagan.

 

[Streetcar]

I don't mind at all carry on but it cracks me up. My thread was about how to wire up a breaker box and it has devolved into half the people talking about bitcoin mining and half the people talking about VFDs. I got the panel wired up and running so life is good.

Bdog
Back to bitcoin. What is the reason (economic value) in bitcoin mining? What does bitcoin originator gain by solving the algorithm