Service Calculations One and Two Family And Multi- Family Paul Revere Chapter May Meeting

Part 2 has a new exception to ( page 68 ) that refers to buildings designed and constructed to comply with an energy code More on this further on in the presentation

Demand factor table that we have had for years. Used when performing what I will refer to as Standard calculation

Single family home consisting of the following loads; 2500 sq. ft. 3 SABC, 1 Laundry circ., 4500va electric dryer, 12kw range, garbage disposal 850va, microwave 1500va, dishwasher 1200va, spa 1500va, va air conditioners,1 electric car charger 7200va va = 7500va 3 = 4500va 1 Laundry Circuit = 1500va Total Gen Ltg load = 13500va First = 3000va 35 % = 3675va Net load gen Ltg = 6675va Electric dryer = 5000va Range = 8000va 4 = 3788va 4 appliances =5050va Electric car charger = 7200va See page 570 Continuous load 2 A C = 12000va = 1500va Total load = 44136va-240= amps General Calculation (Standard)

Remember that you must include the number of small appliance branch circuits that are actually installed not just the two minimum circuits as required. Those of you who work on the larger custom kitchens should be getting the specifications of the appliances to be installed. Many manufacturers now require individual circuits for their equipment ( B). You can then use if you have four or more fixed appliances and take a 25% additional deduction for those appliances.

Optional method of service calculation If you have a dwelling with total connected load of 100 amps or greater Take your general loads as listed in part (B) page 73 List items (1) thru (4) Take the first 10 and take a demand factor of 40% on the remaining load of these items. Then add to that sub total the heating and air conditioning loads as listed in part (C) Items (1) thru (6) whichever applies. Which method will give you the better result???

Single family home consisting of the following loads; 2500 sq. ft. 3 SABC, 1 Laundry circ., 4500va electric dryer, 12kw range, garbage disposal 850va, microwave 1500va, dishwasher 1200va,spa 1500va, va air conditioners,1 electric car charger 7200va va = 7500va 3 = 4500va 1 Laundry Circuit = 1500va Electric dryer = 4500va Range = 12000va 4 appliances = 5050va 4 appliances =5050va Sub total = 35050va 100% = % = Subtotal = 20020va Electric car charger = 7200va See page 570 Continuous load 2 A C = 12000va = 1500va Total load = 40720va-240= amps Optional Calculation

Multi family home consisting of three units with the following loads per unit; 1500 sq. ft. 2 SABC, 1 Laundry circ., 4500va electric dryer, 12kw range, garbage disposal 850va, microwave 1500va, dishwasher 1200va, spa 1500va, va air conditioners va = 4500va 2 = 3000va 1 Laundry Circuit = 1500va Sub total = 9000va First 5100va per unit General lightingx3 = 15300va 3 Electric dryer = 15000va 3-12kwRange = 14000va Based on Table page appliances = 11364va (4 appliance x75%=3788ea) 3-2 A C = 36000va = 4500va Total for 3 units = 96164va-240=400.69amp Standard Calculation

Multi family optional calculation and Table page 74 Can be used if each dwelling has electric cooking equipment, And is equipped with either electric heating and / or air conditioning. House loads shall be calculated based on Part III of article 220 and added to the optional calculation for the dwellings The loads shall be calculated as per (C) items (1) thru (5) as applicable Per unit. The total of the individual dwellings are then added together and a demand Factor from the Table is applied based on the number of dwelling units. Which calculation will give you a more desirable service required??

Multi family home consisting of three units with the following loads per unit; 1500 sq. ft. 2 SABC, 1 Laundry circ., 4500va electric dryer, 12kw range, garbage disposal 850va, microwave 1500va, dishwasher 1200va,spa 1500va, va air conditioners va = 4500va 2 = 3000va 1 Laundry Circuit = 1500va Electric dryer = 5000va Range = 12000va 4 appliances = 5050va 4 appliances A C = 12000va = 1500va Total load per unit = 44550va-240=185amps Total for 3 units = va x 45%= =251amps Optional Calculation

Part 2 has a new exception to ( page 68 ) that refers to buildings designed and constructed to comply with an energy code This basically applies to new commercial buildings under the IECC 2012 code. There are no load tables in the Residential portion of the energy code to follow.

Massachusetts is currently governed by either the IECC 2009 or the IECC 2012 depending on whether the city or town is a Stretch energy community. The following website will get you to a map and list of communities that are Stretch Energy communities. www. Mas.gov/dps Follow the links> Consumer protection> License type>Construction Supervisors license>Stretch energy Or goggle mass stretch energy code and click on Stretch code adoption by community We are now up to 156 communities that have adopted the Stretch code

All NON-stretch energy communities are currently on the 2012 IECC. All buildings except historical are governed by 2012 IECC. All Stretch energy communities are still on the 2009 IECC which covers all building except historic and existing commercial buildings under going renovations ( they are exempt from the stretch code). Existing commercial buildings under going renovations are covered by the 2012 IECC.

All buildings are governed by one energy code or the other. Exception (3) that states; the demand factors specified in are NOT applied to the general lighting load. This rule would apply to new commercial buildings in non stretch energy communities.

C 402 Building envelope requirements C403 Building Mechanical Systems C404 Service Water Heating C405 Electrical Power and Lighting Systems Mandatory Requirements

C 406 Additional Efficiency Package Options Building must comply with this section or the HVAC system is required to have an additional level of energy savings or there Shall be On-site renewable energy systems

Reduced power density Table shall be used and This portion of general lighting is not allowed to use demand factors of for Hospitals list 2 va/sq ft, base energy is 1.2w/ft2, and reduced power Table is 1.1 w/ft2

Section C408 System Commissioning “ NEW 2012 IECC Code requirement” Functional testing of ALL Electrical power and lighting systems install as required by Section C405. Testing will ensure control hardware and software are calibrated, adjusted, programmed And in proper working condition in accordance with construction documents and manufacturers installation instructions. Testing may be required to be an independent party if requested by the inspector. Confirm placement, sensitivity and time out adjustments yield acceptable performance. Confirm that time switches and programmable schedule controls turn off the lights Confirm the placement and sensitivity adjustments for photosensor controls reduce electric light based on usable daylight in the space. DON”T forget the cost of this documentation if you are involved with a new Commercial building in a Non Stretch Energy community!