Shack Construction – Part 2/4 (Electrical, HVAC, And Grounding)


20 KW Generator

20 KW Generator

We put considerable effort into planning the Electrical, HVAC and Grounding systems in our new shack. We have experienced some extended power outages in our area over the past several years and we had been planning to install an automatic generator system for some time. Given the electrical upgrades that we were doing in connection with the construction of our shack, we decided to install a 20 KW automatic generator system as part of the project. The generator also provides a good source of emergency power for our shack. We wanted to have enough fuel capacity to run our house off the electrical grid for a week and this required us to install a large underground propane talk.

Propane Tank for Generator

Propane Tank For Generator

The generator system includes an automatic transfer switch and load shedding system which will automatically start the generator when the power goes off as well as removing heavy loads like the range and air conditioning units should the generator’s capacity be exceeded.

Automatic Transfer Switch

Automatic Transfer Switch

We planned for a number of dedicated 120 VAC and 220 VAC circuits for each operating position in our new shack. These requirements plus the dedicated A/C unit for the room led us to install a separate sub-panel for the shack just outside the room.

Shack Breaker Panel

Shack Breaker Panel

The sizing of the shack’s A/C unit was based upon a heat calculation for the anticipated equipment that might be installed in the shack. As we learned from our experience with our temporary shack, its important to have a good cooling system as the heat that is generated from transceivers, computers, power amplifiers, etc. is considerable. The unit we choose is a heat pump system which can also provide heating should we ever need it during the winter months.

AC Outdoor Unit

A/C Outdoor Unit

We also installed a fresh air exchange system in the room to ensure good air quality during the expanded periods that we planned to be in the room.

Shack Ventilation System

Shack Ventilation System

The next step in this process was to rough-in the outlet boxes, power cabling and HVAC ducts. We also installed low-voltage outlet boxes for Ethernet, Audio/Video services, satellite, cable, etc. connections to our Home Network.

A-V, Networking and Power

A-V, Networking And Power

We installed a generous set of 120 VAC and 220 VAC outlet boxes at each of our two operating positions as well as at the planned equipment construction area. The picture below also show the 2″ PVC conduits that we installed in the thicker standard 2″x6″ rear wall to allow us to route our feedlines and control cables from the ceiling to the floor of our shack.

Outlets by Operating Position

Outlets By Operating Position

The last element of this phase of the project was to build an RF Ground system and cable entry point for our shack. The first thing that we did was to drive a series of 8 ft copper ground rods outside our shack. Each of our two operating positions had three rods 6 ft apart bonded together in a star configuration.

RF Ground Rod

RF Ground Rod

Next, we drilled a small hole through the basement wall at each operating position and ran a heavy ground wire through the wall to the center of the underground rods. This created a very short, direct ground connection for each operating position. These holes were carefully sealed to prevent water leakage into the room.

Ground Entry in Shack

Ground Entry Into The Shack

Finally, we installed a ground block for mounting PolyPhaser Coaxial Lightning Protectors for our feedlines as they enter the shack. We also installed a section of 3″ PVC pipe to allow our feedlines to pass through the outside of the shack into the room. The 3″ PVC conduits in the ground by our shack entry lead to our existing antennas. We plan to install additional larger 6″ PVC conduits in the future to accommodate hardline feedlines to a future tower.

Cable Entry Outside Shack

Cable Entry Outside The Shack

With this stage of the project completed, we were ready for insulation, drywall, ceiling and floor installation. These steps will be the subject of our next post.

– Fred (AB1OC)

3 thoughts on “Shack Construction – Part 2/4 (Electrical, HVAC, And Grounding)

  1. The PVC conduit in the picture of the original shack entry uses 3″ conduits. These are adequate for control cables and 3-4 runs for a modest side feedline like LMR-400 UltraFlex. When we installed our tower we added additional 6″ conduits to accommodate our hardline feeders which are much less flexible.

  2. Thanks so much for the information, working on my shack and planning on using the same PVC concept to run cable.. have to figure out exactly what I can fit in the 2×4 walls.

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