Parallel Offset Calculator
Key Takeaways
- Each conduit in a parallel rack needs a different travel distance
- Spacing between conduits determines the travel adjustment per conduit
- Shrink per conduit stays constant when all offsets have the same depth
Contents
What Are Parallel Offsets?
Parallel offsets occur when multiple conduits running side by side in a rack all need to make the same offset. The challenge is that each conduit must maintain equal spacing before, during, and after the offset. To accomplish this, each successive conduit requires a longer travel distance between its two bends.
Without adjusting the travel for each conduit, the conduits would converge at the bend points and no longer be parallel. The outer conduits need more travel because they are covering the same vertical offset but over a wider horizontal distance.
The Formulas
1st Conduit Travel = Offset Height × Multiplier
The shrink is the same for all conduits because they all make the same depth offset. The total spread is the horizontal distance from the first conduit's bend to the last conduit's bend.
Example: 3 Conduits, 6" Offset, 30°, 2" Spacing
- 1st conduit travel: 6 x 2.0 = 12 inches
- 2nd conduit travel: 12 + (2 x 2.0) = 16 inches
- 3rd conduit travel: 12 + (2 x 2.0 x 2) = 20 inches
- Shrink (all): 6 x 1/4 = 1-1/2 inches
- Total spread: 2 x (3 - 1) = 4 inches
How to Bend Parallel Offsets
Follow these steps when bending a rack of parallel conduit offsets:
- Determine the offset height, bend angle, conduit spacing, and number of conduits
- Calculate the travel for the first conduit using the standard offset formula
- For each additional conduit, add the spacing times the multiplier to the previous travel
- Mark each conduit with its specific travel distance
- Account for shrink on all conduits (it is the same for each)
- Bend the first conduit, then use it as a reference to align the subsequent bends
Frequently Asked Questions
How do you calculate travel for parallel conduit offsets?
The first conduit uses the standard formula: travel equals offset height times the bend multiplier. Each subsequent conduit adds the conduit spacing times the multiplier to the previous conduit's travel. This ensures all conduits maintain equal spacing through the offset.
Why do parallel conduits need different travel distances?
When multiple conduits run parallel through an offset, the outer conduits must travel a greater distance to maintain equal spacing. If all conduits used the same travel distance, they would converge and bunch together at the bend points.
What is the best bend angle for parallel offsets?
30 degrees is the most popular angle for parallel offsets because of its simple 2x multiplier. However, for shallow offsets with many conduits, 22.5 or even 10 degrees can work better because the total spread between bends is more manageable. For tight spaces, 45 degrees minimizes travel distance.