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Groover's avatar
Groover
Explorer II
Nov 23, 2015

Intellitec Bi-Directional Isolator fried

After noticing that my house batteries were not charging while driving I did some checks and found both the Intellitec controller and Trombetta relay that make up my battery isolator were fried. I opened up the controller and could see a burnt area on the circuit board. The relay still clicks when power is applied to the solenoid terminals but the high amp contactors don't make. My guess is that as the controller failed it delivered lower voltage to the relay and let it start chattering which then burnt the contacts in it.

I replaced both components and found that both of the new components get hot. I was seeing a 40 degree temperature rise on the case of the controller and 80 degree rise on the relay near the solenoid terminals. Tests showed that the relay draws about 1.8 amps and I was getting about a 2.5 volt drop in the controller. The relay is rated for continuios operation but I have not been able to find any specs on the Intellitec relay. To be on the safe side I bought a smaller relay (for controlling cooling fans) from a parts house and wired it handle the power for the Trombetta relay. The Intellitec now only has to power the smaller relay which only draws about 1/10th as much amperage. The Trombetta is still hot but at least the Intellitec is cool.

My suspicion is that the Intellitec controller is not meant to directly control a relay like the Trombetta. I have called technical support at both Thor and Intellitec and have not been able to speak with anyone that has a clue as to whether I am right or wrong. Regardless, I am going to leave it this way. My hope is that this will help any other people that have had failures for Intellitec relays.
  • Groover wrote:
    dougrainer wrote:
    The Intellitec Relay is rated at 100 amps DC current. Doug


    The coach builder did not use an Intellitec relay but used the Trombetta instead. What I would like to find out is how much power the Intellitec control board is rated for.


    Curious, WHERE did you get the idea to call that solenoid a Trombetta? That term is almost unheard of. The ONLY place I have heard and used that term was on LCI hydraulic leveling/stabilizing systems. It can mean a solenoid OR a Valve. The Intellitec BI directional (BIRD) is usually on a 15 or 20 amp DC fuse. ALL the BIRD does is react to various signals and send a 12 volt signal to a solenoid. It is NOT designed to sustain any HI current. There are various BIRD Intellitec systems. Can you post a pic of your particular system? Doug
  • dougrainer wrote:
    The Intellitec Relay is rated at 100 amps DC current. Doug


    The coach builder did not use an Intellitec relay but used the Trombetta instead. What I would like to find out is how much power the Intellitec control board is rated for.
  • enblethen wrote:
    The relay, is it mounted on the circuit board as a control relay? These may be rated only .5 to 5 amps.
    The large relay(some call it a solenoid) would be rated for 100 amps.


    The controller has a 12V output that was factory wired to the solenoid on the large relay. That is the one that draws about 1.8 amps and was making the controller heat up. I redirected the output from the controller circuit board to a smaller relay that in turn now drives the big relay.
  • The relay, is it mounted on the circuit board as a control relay? These may be rated only .5 to 5 amps.
    The large relay(some call it a solenoid) would be rated for 100 amps.