Free Electrical Estimating Training #6
Estimating Electrical Projects does not have to be hard.
Continued from lesson #5
Specifications
Read the specifications carefully to determine the type of raceway and fittings you will be using. Record the required device types along with the corresponding faceplates. When applying your assembly, if you are including the complete raceway system, ensure that you include ____ couplings per ____ feet of the raceway.
Additionally, adjust your straps and connectors in the same manner. In previous lessons, we counted:
- 9 duplex receptacles
- 5 GFI receptacles
- 1 GFI with a weatherproof cover
- 1 single receptacle
We will input the following counts into the Electrical Solutions software. This is just a portion of the sheet we used. The same procedure can be applied to multi-story buildings with thousands of devices.
The goal is to cover costs while spending as little time as possible on switches and receptacles. The larger feeders will account for most of the expenses, so ensuring accuracy with these items is essential.
Be cautious: when counting screws and wing nuts, fatigue can lead to mistakes on the more critical components. Averaging is an effective way to account for raceway and conductors for these items. While we are not opposed to individually scaling each device, feel free to use that method if it makes you more comfortable.
Note: You should feel confident about your estimate.
Stub Ups
Stub-ups refer to empty raceways installed from a box to above an accessible ceiling. These are typically ¾” EMT run from a box with a plaster ring to above a dropped ceiling. Some type of bushing is installed on the open end, with a pull wire included for other trades to run cable at a later date.
Review the Electrical Symbol Schedule shown below. You will notice that there are 8 different types of symbols, but all 8 require the same amount of material and labor. The choice is left to the estimator; some estimators will group all 8 symbols into one takeoff, while others will separate them into distinct assemblies.
Telephone Data Cabl
If you are not installing the conductors and jacks, I recommend combining them all into one unit. As before, we need to assemble the items that will be used for each stub-up. The following materials are required:
1. 10’ ¾ EMT
2. 1 – 4×4 box with a bracket
3. 1 plaster ring
4. 2/3/4” straps
5. 2 – 3/4” connectors
6. 1 – 3/4” plastic bushings
7. 4 tek screws
8. 14’ string
Feeders
The definition of a feeder is: A circuit conductor between the power supply source and a final branch circuit overcurrent device. In estimating, it is common to include other runs of conduit and wire in the feeder portion of an estimate, even if they do not fall under the NEC’s definition of a feeder, and that’s acceptable. The goal is to encompass everything, regardless of what it is called. For example, we show a MDP Panel, Panel A, and Panel B. The conductors powering Panel A and Panel B are feeders. It’s important to note that, in real installations, you seldom run the shortest distance between these points.
You will often run the raceway at angles relative to the building structure, and you will have sections of conductors for the risers—whether they run overhead or underground—resulting in increased distance. Additionally, you will need extra conductor length for terminations. Therefore, you cannot simply draw a straight line between the MDP and Panel A and use that length for your final footage. Below is a sample feeder takeoff sheet. There is no right or wrong way to collect this information, so feel free to create your own method. The sample below is designed for a pen-and-paper estimator who needs to gather more information than a software estimator. As you measure each feeder, record it in the manner shown below and then transfer it to your estimate. In our example, we have collected information from the MDP to Panel A. We have titled the entry and noted the size of the needed raceway.
Next, we document the type of raceway and the number of 90-degree bends required. We also record the connectors, bushings, couplings, and straps necessary for the installation. Next, we capture the length of the run, including any vertical distances that may be required. Finally, we note the wire needed for the installation, which includes the number of wires, their sizes, and any additional length required for terminations. You may choose to create a feeder takeoff sheet that is tailored to your needs.
Electrical Takeoff Sheets
When choosing a product, you can use Electrical Solution’s Takeoff Sheets, as shown below, or enhance your workflow with a digital takeoff solution like Digi Count Takeoff Pro by Best Bid. Recording feeders can be quick and straightforward, but this is where significant costs can arise, so take the time to measure carefully. Your checklist should include the following items:
1. Aluminum or copper conductors
2. EMT, PVC, or rigid raceways
3. PVC or rigid 90-degree bends for underground feeders
4. Backfill using existing material or concrete
5. Single run or parallel configurations
6. Seismic supports
7. Grounding bushings
Electrical estimators and Electrical Contractors use Electrical Bidding software to make these task much easier.
Feel free to add any additional items to your list as they come up. It’s helpful to identify each feeder by name so you can provide the installer with a detailed breakdown of time and materials for each feeder.
HVAC
Almost every project will include heating and air conditioning. Before starting your takeoff, be sure to review the specifications to confirm the following information:
1. Voltage and phase for the units
2. Type of disconnects: are they fusible or non-fusible?
3. NEMA configuration (NEMA 1, NEMA 3R, NEMA 12, etc.)
4. Are the units heavy-duty or regular?
5. Are special fuses required?
6. Are rejection clips needed?
7. Who is responsible for supplying the controls, cables, and starters, if applicable?
8. In some cases, the disconnects may be included with the units.
9. Additionally, GFI receptacles may also be included with the units.
Make sure all necessary details are accounted for before proceeding.
We will continue in lesson #7
