Installing a Fan Timer Device

[Dbates001]

Hello. I have a MSTR3 base Station ready to put into service. Since the site is now 100% solar with battery backup, would like to add a timer/relay device so that the fans on the PA don't run 24/7. Where is the best point to connect the trigger wire for the timer ? I am thinking maybe a five second initial delay with a duration about a minute or so after the last transmission drops.

DaveBates, KF0XQ

 

[prcguy]

Hello. I have a MSTR3 base Station ready to put into service. Since the site is now 100% solar with battery backup, would like to add a timer/relay device so that the fans on the PA don't run 24/7. Where is the best point to connect the trigger wire for the timer ? I am thinking maybe a five second initial delay with a duration about a minute or so after the last transmission drops.

DaveBates, KF0XQ

Fans usually have a longer life running continuous rather than cycling on and off. And a solar site should be able to handle a fan, otherwise its probably not designed right. Anyway, I would look for a point that goes high or low with the transmitter on then make a timer that will get initiated by that line then run awhile after the transmit line changes state.

 

[merlin]

Just food for thought, I would use a thermal control that would vary the fan on demand for temperature.
The fans run slow with low heatsink temperature then increase as needed for high temperature.
Like prcguy said, solar power will handle that if designed right.

 

[mmckenna]

I've got 3 repeater sites that are fully solar.
The enclosures that someone purchased (not me) had temperature controlled fans pre-installed.
They've been in there since ~2016 or so, and have been running fine without issues, but I expect that they'll eventually fail.

It works well since there is more in the enclosure than just the repeater. There's some minor network equipment that connects the repeater sites together, and that all generates a bit of heat. The box itself is mostly white, but still absorbs enough heat to be a concern.

The fan will cycle on and off periodically, and it's kept everything healthy. But the repeaters are turned down to 10 watts, so not a huge amount of heat, plus they don't see a lot of traffic.

 

[wa8pyr]

The fan will cycle on and off periodically, and it's kept everything healthy. But the repeaters are turned down to 10 watts, so not a huge amount of heat, plus they don't see a lot of traffic.

That’s a good point; set the TX power on your MASTR3 to the lowest power necessary for effective communication over your service area (you should do this anyway, no matter what your power source is). You don’t want an “alligator“ with a big mouth and little ears.