When installing a UT20 or UT30 universal tower from Campbell Scientific, it is critical to securely mount the tower on a firm foundation for long-term use. In this video, we'll install the tower in a concrete block using the UTBASE. When compared to the B18, The UTBASE does not require the bottom tower section so the UTBASE can be installed prior to the tower installation, letting the concrete fully cure.
This video covers installing the UTBASE with the stainless-steel anchor kit and template options in new concrete. A concrete anchor kit is also available for installing the UTBASE in existing concrete. Tools required to install the UTBASE include: Philips screwdriver Two 9/16 wrenches 1-1/8 wrench Level Shovel Cordless screwdriver And a Hammer To begin, prepare the site for installation.
The UT20/UT30 manual contains siting and exposure recommendations. Remove any vegetation, rocks, or debris close to the installation site. Otherwise, disturb the vegetation and ground surface as little as possible.
Dig a hole 36 inches by 36 inches by 48 inches deep. Move the soil from the hole outside the cleared area. The UTBASE can be installed with or without framework.
The main advantage of installing the UTBASE using a template frame is it allows the installer to leave the installation site immediately after the concrete is placed, rather than having to wait for the concrete to cure to ensure a level base. The template frame also provides a stable anchor point if conduit is being installed. The concrete form and template frame hold the UTBASE securely in position until the concrete cures, ensuring a level base and plumb tower.
The template can be assembled prior to traveling to the installation site or after arriving at the site. First, cut the lumber needed to build the concrete form and template frame. Ensure the lumber is straight with no warping.
Using 2x4 lumber, cut the following lengths: Two at 60 inches Two at 36 inches Two at 43 inches Additionally, you will need four stakes approximately 12 to 24 inches long for the corners of the frame. Make a line 10. 5 inches from each end on both the longer pieces of lumber.
While ensuring the frame remains square and flat, place a 36-inch piece of lumber between the two longer pieces of lumber at the mark. Repeat with the second 36-inch piece of lumber at the second mark to create a 36x36 inch form. Secure all four pieces together with wood screws.
The template consists of three pieces. Assemble the template by securing the pieces together with a -20 template screw at each corner. Thread a nut onto each UTBASE anchor bolt and slide each bolt through the template.
Thread a second nut onto each anchor bolt just enough to cover the end of the threads. Tighten the lower nut to secure the template against the upper nut on each anchor bolt. Rest the two 43-inch long 2x4s across the concrete form, then set the template on the 2x4s so one 2x4 lines up with the inside edge of one template piece and the other is under the tip at the opposite side.
Secure the template to the 2x4s. Center the template assembly inside the concrete form and secure the 2x4s to the concrete form. At the installation site, place the concrete form over the open hole.
Orient the form until one edge of the template faces the equator. This arrangement is optimal for mounting a solar panel on two tower legs facing the equator. In instances where a crossarm needs to run perpendicular to the equator, such as precision pyranometer measurements, rotate the template frame such that a crossarm can be run across two tower legs running north and south.
Drve a stake into the ground at each corner of the concrete form. Level the form and secure it in position. Leveling the template ensures the anchor bolts are vertical.
Fill the hole with concrete To the upper edge of the outer frame Screed the concrete. Allow three to four days for the concrete to cure. Skip the following section, UTBASE Installation Without a Template Frame, and proceed directly to Clevis Installation.
Use the link in the description below to skip to Clevis Installation. This section covers installing the UTBASE without using a template frame. See the previous section, UTBASE Installation With a Template Frame, for instructions on using the template frame.
The main advantage of installing the UTBASE without using the template frame is not needing to build the template frame. The concrete form is also optional in this installation. The disadvantage to this method is the installer must remain at the installation site, checking to ensure the UTBASE remains level until the concrete cures enough to prevent the UTBASE from shifting.
Begin by assembling the template pieces and securing them with a template screw at each corner. Thread a nut onto each UTBASE anchor bolt and slide each bolt through the template. Thread a second nut onto each anchor bolt just enough to cover the end of the threads.
Tighten the lower nut to secure the template against the upper nut on each anchor bolt. Optionally, build the concrete form out of two 60-inch 2x4s and two 36-inch 2x4s and place the form over the hole using stakes in the corners and level the frame. Fill the hole with concrete and screed the surface.
Orient the template so one side faces the equator. This arrangement is optimal for mounting a solar panel on two tower legs facing the equator In instances where a crossarm needs to run perpendicular to the equator, such as precision pyranometer measurements, rotate the template frame such that a crossarm can be run across two tower legs running north and south. Center the template over the wet concrete, anchor bolts pointing down.
Shake the template as the bolts go into the concrete to reduce the chance of voids in the concrete along the anchor bolts. Stop pressing when the concrete reaches the threads on the anchor bolts. Ensure the template is level using a level.
For the next several hours, periodically check to ensure the template remains level as the concrete cures. Keeping the template level is critical so the tower can be leveled and ensures the holes in the UTBASE line up with the tower legs. Once the concrete has set to the point there is no longer a chance for the anchor bolts to settle, it is okay to leave the site.
Allow three to four days for the concrete to cure. Return to the installation site and remove the template, nuts, and masking from the anchor bolts. Also remove the template frame and concrete form, if present.
Apply anti-seize lubricant to the three anchor bolts. Thread a clevis onto each anchor bolt until a few bolt threads are visible inside each clevis. If the clevis is threaded too far onto the anchor bolt, the tower may not be able to tilt Determine which direction the tower will tilt to the ground and turn the clevises to match that direction.
Generally, the tower will tilt in one of the two directions away from the equator to protect the solar panel mounted on the tower. Attach the three connecting tubes to the bottom tower section using the shorter 3/8 bolts. Make sure the flat portions on each connecting tube are parallel.
With the bottom tower section laying horizontally in the direction the tower will tilt, position the two legs resting on the ground into the two clevises facing the tilt direction. Insert one 2. 75-inch mounting bolt through the upper hole of the two clevis pins with a connecting tube.
Then pass the bolt through the connecting tube upper hole and out the other side of the clevis. Finger-tighten a nut on each bolt, then tilt the tower up into place, which might require pulling or pushing on the tower leg if it has been bent at all in shipping. Insert a bolt through the third clevis and connecting tube.
Use a level to check if the tower is plumb. If not, remove the 2. 75-inch bolt from the leg needing adjustment and turn the clevis clockwise to lower the leg and counterclockwise to raise the leg.
Reattach the connecting tube to the clevis and check for plumb. Continue making fine adjustments until the bottom tower section is plumb. Then add the remaining bolts that connect the clevis and connecting tubes.
The UTBASE is now ready to support a fully-assembled UT20 or UT30 universal tower. Contact Campbell Scientific if you have any questions on the installation of the UTBASE.
