Key Takeaways
- Four-point saddles are ideal for larger obstructions.
- Aluminum conduit is lighter and easier to bend.
- Proper bend angles simplify conduit installation.
Understanding Four-Point Saddles
Comparison to Three-Point Saddles
A four-point saddle is ideal for large or long obstructions. The design consists of four bends: an offset up, a traverse across the obstruction, and an offset back down. This ensures the conduit clears the obstruction efficiently, which is particularly useful when dealing with larger objects.
In comparison, a three-point saddle is typically used for smaller obstructions like a piece of conduit on a wall. It involves three bends: the initial rise, the apex or hump, and the descent. This method works well for objects up to approximately 2 inches in size. The difference between the two lies in the complexity of the bend, with the four-point saddle providing extra clearance over bigger obstructions.
Applications for Large Obstructions
When you have a large obstruction, like a 6-inch-high object, using a four-point saddle is effective. You begin by measuring the distance to the object and marking the conduit for each bend. Use a multiplier for your bends to ensure smooth rising and descending angles. A common choice is a 30° bend with a 2x multiplier, which offers a balance between gentle and aggressive bending.
Accounting for conduit shrinkage is important. Many practitioners add a bit extra to compensate, ensuring the final layout is precise. Aluminum conduit is often preferred for these tasks due to its lighter weight and ease of bending compared to steel. If extra coating like "Blue Lightning" is used, it even reduces wire-pulling resistance.
Preparations for Bending a Four-Point Saddle
Marking the Conduit
The process begins by determining the distance to the obstruction you need to cover. Mark this measurement as your first bend point. Use a pencil for marking to ensure any errors are easily erasable. Number each mark sequentially—1, 2, 3, and 4—to keep track of their positions.
Considering Shrinkage
Shrinkage occurs naturally during bending, as the conduit length slightly decreases with each bend. While precise projects may require accounting for shrinkage, in most field applications, a bit of additional length is added to fudge the numbers. If needed, you can trim the conduit at the end to ensure uniformity.
Measurement Strategies
Start by measuring the height and length of the obstruction. For example, with a 6-inch high object, using a 30° bend with a 2X multiplier is preferred. This multiplier means 6 times 2 equals 12, providing the appropriate offset. Mark the conduit accordingly for all four bends, and remember the order: you bend the first two, then mirror the same on the opposite side.
Step-By-Step Bending Process
Measuring to the Obstruction
First, measure the distance to the obstruction you need to traverse. For example, if the end is at 59 inches, mark this spot, labeling it as Bend Number 1. Use a pencil for marking, as it allows for easy adjustments. Avoid using a Sharpie; it is for demonstration purposes only.
Calculating Offset Height
Next, determine the height of the object you are offsetting over. With a 6-inch height, use a 30° bend and a 2X multiplier. Thus, you multiply 6 by 2, resulting in 12 inches. Mark this as your Bend Number 2. Choosing a gentle 30° bend reduces wire-pulling difficulty, which would be greater with a sharper bend.
Marking the Length
Locate the length of the obstruction, which in this case is 9.5 inches. Return to your previous markings and add this length. Mark 9.5 inches from the second point and identify it as Bend Number 3. Using clear measurements helps ensure accuracy throughout the process.
Completing the Offset
Finally, create another offset like the first. Multiplying the 6-inch height by 2, again gives 12 inches. Add this next to your conduit’s end, marking it as Bend Number 4. Understand that the order of the bends is crucial: you need Bend 1 and 2, then reflect and replicate the bend pattern for Bend 3 and 4.
Effective Techniques for Bending Conduit
Choosing Bend Angles
Selecting the right bend angle is crucial for successful conduit bending. When dealing with a four-point saddle, you typically have options like 30°, 45°, 60°, and 22.5° bends. A 30° bend offers a balance — gentle enough for easy wire pulls while giving a smooth offset. If the obstacle is around 6 inches tall, using a 30° bend with a 2X multiplier can provide sufficient clearance.
Using a 45° bend results in a more aggressive angle, suitable for more abrupt transitions. Remember, the more aggressive the bend, the harder it is to pull the wire through. On the other hand, a 60° bend might be too steep, making it challenging to manage in some situations. Your choice should align with the size of the obstruction and the specifics of the project.
Using the Proper Bender Orientation
Orientation of the bender is vital. First, align the shoe’s arrow with the measurement mark on the conduit. Ensure the arrow points away from you, pulling the object end towards you when stepping on the bender.
As you prepare to bend, place the conduit firmly on the ground. Apply downward pressure with your foot, not by pulling with your arms. The shoe should act as a guide rather than the tool driving the entire process. Different benders may have varying configurations, so ensure yours is aligned correctly for the specific angle you're attempting.
Maintaining Bending Consistency
Consistency is achieved by carefully measuring and marking each part of the conduit. For even bends, always start from your previously determined marks. Employ a pencil for marking; it’s easier to adjust without permanent residue.
To ensure uniformity, particularly in a four-point saddle, mimic the pattern on both sides — bend points one and two, then mirror for points three and four. Aluminum conduits are lighter and easier to bend than steel, providing an advantage in maintaining consistency. With aluminum, avoid over-tightening, as it can cause indentation easily.
By following these techniques, you can achieve precise and reliable results, ensuring the conduit fits snugly and securely, conforming to project requirements.
Advantages of Aluminum Conduit
Weight and Ease of Bending
Aluminum conduit is significantly lighter compared to other materials, which makes it much easier to handle. When you need to bend conduit, aluminum is more manageable compared to steel. This improved maneuverability is especially noticeable when dealing with larger sizes. The lightweight nature minimizes fatigue, allowing you to work more efficiently on longer projects.
Cost Comparison with Steel
In terms of cost, aluminum conduit is generally more affordable than steel. The lower price point can make a considerable difference, especially for large-scale installations. Choosing aluminum can lead to reduced overall expenses, offering the same functionality without the higher costs associated with steel.
Benefits of the Blue Lightning Coating
Aluminum conduit with the Blue Lightning coating enhances the ease of pulling wires through the conduit. This coating, similar to Teflon, significantly reduces resistance, allowing wires to glide through smoothly. This feature addresses one of the common challenges with aluminum, where it might catch slightly more than steel, ensuring a seamless installation process.