Since Unirac no longer manufactures their Top of Pole Mount product line anymore and they have limited availability in their stocks, most installers started switching to IronRidge and DPW pole top products.
One of the most frequently asked questions about pole top mounts is the number of modules that would fit on a particular product. The calculation for this is very simple. Before going into the details on how to do this manually, the easiest way is to visit IronRidge's website and check their Pole Mount Configurator. Most of the modules in the solar pv market are included in the configurator. It tells you which Top of Pole or Side of Pole mount product you'd use and the number of modules that would fit on it.
In this article, I will give you the basics:
First, you need to know the dimensions of your module. Let's say that we spec for (12) x Schuco SPV 215 SMAU modules, which has dimensions of 55.79 x 36.9 inches. It's going to be a 2.5 kW project on the backyard of a house, since the roof is not suitable for penetration (or is unsuitable for another reason, such as obstacles or shading).
- Top of Pole Mount products are generally larger than Side of Pole Mounts. Therefore, I start by looking at the TP/12. The channel rail length is 140" for the TP/12. It means that I can fit only up to 3 modules in landscape style on the channel rails. ( 140" / 36.9" >= 3.7 )
Even though the installation guide of the TP/12 tells me that I can fit 6 rows by 2 columns, I realise that I can only fit 3 rows by 2 columns.
- To verify that 2 columns would fit, I need to do another simple calculation. The channel rails will attach to the bottom hole of the module which is 17" off the module end. The total module span would be 55.8" x 2 = 111.6 inches.
- By substracting the 17" hole distance from the total span: 111.6" - (2 x 17") = 77.6 inches. This is longer than 77.36" (TP/12), but shorter than 101.87" (TP/12LL).
Once this information is verified, I can say that I can fit 6 modules with the orientation of 3 rows of 2 columns on a TP12LL.
For a system that consists of 12 modules, I need two TP12LL Top of Pole Mounts.
To read further about the installation of Top of Pole mount, please download the installation manual (.pdf) for IronRidge Top of Pole Mounts.
| IronRidge Part Number | Max. No of panels | Channel Rail Length (attaches to the module) |
Cross Rail Length (attaches to support channel rail) |
Pipe Diameter Size Schedule 40 |
| Top of Pole Mounts | ||||
| UNI-TP/02 | 2 (one column) | 45" | 40" | 4.0" |
| UNI-TP/02A | 2 (one column) | 55" | 40" | 4.0" |
| UNI-TP/03 | 3 (one column) | 70" | 40" | 4.0" |
| UNI-TP/04 | 4 (one column) | 90" | 40" | 4.0" |
| UNI-TP/04A | 4 (one column) | 110" (55" & 55") | 40" | 4.0" |
| UNI-TP/06 | 6 (two columns) | 70" | 77.37" | 6.0" |
| UNI-TP/06LL | 6 (two columns) | 70" | 101.87" | 6.0" |
| UNI-TP/08 | 6 (two columns) | 90" | 77.37" | 6.0" |
| UNI-TP/08LL | 6 (two columns) | 90" | 101.87" | 6/0" |
| UNI-TP/10 | 10 (two columns) | 115" (45" & 70") | 77.37" | 6.0" |
| UNI-TP/10LL | 10 (two columns) | 115" (45" & 70") | 101.87" | 6.0" |
| UNI-TP/12 | 12 (two columns) | 140" (70" & 70") | 77.37" | 6.0" |
| UNI-TP/12LL | 12 (two columns) | 140" (70" & 70") | 101.87" | 6.0" |
| IronRidge Part Number | Max. No of panels | Distance between module mounting holes | Combined width of panels | Pipe Diameter Size Schedule 40 |
| Side of Pole Mounts | ||||
| UNI-SP/01 | 1 | 26.9" ± 5" | 25" | 2.0" to 4.5" |
| UNI-SP/01A | 1 | 26.9" ± 5" | 27" | 2.0" to 4.5" |
| UNI-SP/01XH | 1 | 37.125" ± 5" | 27" | 2.0" to 4.5" |
| UNI-SP/01XX | 1 | 37.125" ± 5" | 30" | 2.0" to 4.5" |
| UNI-SP/02 | 2 | 26.9" ± 5" | 45" | 2.0" to 4.5" |
| UNI-SP/02A | 2 | 26.9" ± 5" | 55" | 3.0" to 4.5" |
| UNI-SP/02X | 2 | 37.125" ± 5" | 55" | 3.0" to 4.5" |
| UNI-SP/03 | 3 | 26.9" ± 5" | 70" | 4.0" to 4.5" |
| Single Arm Pole Top | Inside extrusion dimension | |||
| UNI-SA/14.0 | 1 | 5.0- 12.6" | 2.0" to 4.5" | |
| UNI-SA/21.5 | 1 | 12.6 - 21.1" | 2.0" to 4.5" | |
| UNI-SA/26.0 | 1 | 15.6 - 26" | 2.0" to 4.5" | |
Comments
Thanks for this great article on sizing Ironridge Pole Mount racking. Question, what material are the East West rails made of for the top of pole mounts and what material are the North South rails made of for the top of pole mounts?
IronRidge rails are not iron. :)
The channel rails are finished aluminum and the cross rails are powder coated steel.
> Installation Manual of IronRidge Top of Pole Mounts (pdf)