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Grain Bin Clearances


The State of Iowa requires specific clearances for electric lines around grain bins, with different standards for those filled by portable augers, conveyors and elevators and permanent equipment.
If you’re planning to build or move a grain bin, either on your property or for someone else, you need to be familiar with Iowa’s law on required distances from overhead electric lines. This law was put in place to provide protection from the hazard of contacting overhead electric lines to anyone working around grain bins with augers, elevators, or other equipment.

The drawings inside this brochure show the specific clearance requirements related to permanently installed augers and portable augers. There must be at least 18 feet between the top of any grain bin and any overhead electric lines. These distances were developed by the American National Standards Institute. Figure 232.4(b) can be found in the February 6, 2012, “Errata to 2012 Edition National Electrical Safety Code (NESC)” and the 2012 NESC.  As your electric service provider, we’re responsible for ensuring that these specifications are met.  In fact, in any situation where minimum clearance requirements are not observed, the utility may refuse electric service.

So if a new grain bin is on your list of projects, please give us a call 319-683-2510. We will work with you in developing a site plan for your project.


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Fig. 234-4(a) -- Clearance Envelope for Grain Bins

Filled by Permanently Installed Augers, Conveyors, or Elevators

P    = probe clearance 5.5m (18 ft.)

H    = horizontal clearance 4.6m (15 ft.)

T    = transition clearance

V1  = vertical clearance above a building required by

         Rule 234C (Table 234-1)

V2  = vertical clearance above land required

         by Rule 232B (Table 232-1 or 232-2)


Figs. 234-4(b) Clearance Envelope for Grain Bins

Filled by Portable Augers, Conveyors, or Elevators