200 AMP Breaker vs 150 AMP Breaker

[kayla]

I recently had an inspection on my home and the inspector states this:

"As discussed during the inspection, 150 AMP electrical service probably is not enough for a 2700 square foot house in 2003."

We built this house in 1997 and have not had any electrical problems. Heating is gas, everything else is electric. Can you please let me know the code...the inspector my agent uses says this is a bunch of BUNK!!

 

[roger]

Re: 200 AMP Breaker vs 150 AMP Breaker

The inspector your agent uses is right.

It is true that 200 amp services are the "norm" nowadays, but not necessarily needed.

If you actually applied the calculations in article 220 you would have plenty to spare with your 150 amp service.

I just made a quick run using the optional method assuming you could possibly have the following.

2700 SQ'
two small appliances
one laundry
8000 watt range
4000 watt water heater
dishwasher 2000 watt
disposal 850 watt
compactor1000 watt
dryer 4000 watt
a 1 hp pump

With this, I came up with less than 110 amps.

Roger

 

[canman]

Re: 200 AMP Breaker vs 150 AMP Breaker

In Mike Holts free stuff there is a residential load calculator into which you can enter your homes various loads and obtain a close answer to your total load.

 

[bob]

Re: 200 AMP Breaker vs 150 AMP Breaker

I came up with a slightly different caculation result.

Gen lts 2700 sq ft 8100
2 app ckts 3000
2 laundry ckts 3000
--------
total 14100
first 3000 @ 100% ******** 3000
11410 @ 35% ******** 3885
Total 1 **** 6885


App load
1 wh 4500
1 Ref 1400
1 Freezer 600
1 DW 1030
1 Disp 700
1 Microwav 1000
--------
Total 2 9230

4 TA/C Unit 6300
Range ----- 8000
Dryer ----- 5000
-------
Total 3 19300

Total 1 2 and 3 = 35415
Amps at 240 volts = 148 amps

[ May 13, 2003, 03:46 PM: Message edited by: bob ]

 

[roger]

Re: 200 AMP Breaker vs 150 AMP Breaker

Bob, a couple of questions.

Why two laundry circuits? Code only requires one for service calculation.

Why figure Ref, Freezer, and Micro wave? These are plug and cord connected appliances, which would come under the two small appliance circuits.

However, using your numbers I used the optional method and still only see 112 amps

I'm just showing your numbers below.

8100
3000
3000
4500
1400
600
1030
700
1000
8000
5000
----

36330

First 10000 @ 100% = 10000
Remaining 26330 @ 40% = 10532
A/C = 6300
_____

Total 26832


26832 / 240 = 111.8

Roger

 

[jro]

Re: 200 AMP Breaker vs 150 AMP Breaker

Here I go, Example D2(b)

2700 sq ft x 3 = 8100
small appli. 3000
laundry 1500
oven 4000
cooktop 5100
water heat. 4500
dish wash. 1200
washer/dryer 5000
______
32400
1st 10kva @ 100% 10000
remainder @ 40% 8960
_____

78960
AC60AMP 14400
_____
33360/240 = 139 amps

 

[bob]

Re: 200 AMP Breaker vs 150 AMP Breaker

Roger
I was going a little high just to counter the inspectors comment. Is still is less that the 150 amps.

 

[roger]

Re: 200 AMP Breaker vs 150 AMP Breaker

Bob, I am a little slow at times, I see now where you were going. I appologize.

Jro's example is also below 150 a

We haven't seen much of you since the forum changed, I hope you become more active again.

Roger

[ May 13, 2003, 08:21 PM: Message edited by: roger ]

 

[peter]

Re: 200 AMP Breaker vs 150 AMP Breaker

So far we have four different calculations from four distinguished, experienced electrians:
110
148
112
139
This is very comforting for some reason.
~Peter

 

[jro]

Re: 200 AMP Breaker vs 150 AMP Breaker

Peter its "experienced electricians" . Just messing with you, but its good to put our brain buckets together, I really enjoy this and find it very informative.

 

[bob]

Re: 200 AMP Breaker vs 150 AMP Breaker

Peter
Thanks for the compliment but I'm not an experienced electrician. I'm a PE.