jbrown40004 Posted April 30, 2014 Report Share Posted April 30, 2014 This is a personal project question but the situation coult possibly come up in a HI. I am installing a multi-split hydronic HVAC system in my home. The fan-coil units require 220V to each unit and I will be installing 3 fan-coil units. There is a transformer in each fan-coil unit that steps down the voltage and converts it to DC. I only have room for two more 220V circuits in my panel. For the installation I will need a total of four 220V circuits if I need to run a dedicated circuit to each fan-coil. 3 circuits for the fan-coils and 1 circuit for the outside unit. The fan-coil units only draw less than 1 amp each max. The electrician is telling me that I can not run all three fan-coil units on one 220V circuit because each fan-coil unit has a DC motor in it(code issue). Could someone confirm this for me? Thanks Quote Link to comment Share on other sites More sharing options...
Scottpat Posted April 30, 2014 Report Share Posted April 30, 2014 This is a personal project question but the situation coult possibly come up in a HI. I am installing a multi-split hydronic HVAC system in my home. The fan-coil units require 220V to each unit and I will be installing 3 fan-coil units. There is a transformer in each fan-coil unit that steps down the voltage and converts it to DC. I only have room for two more 220V circuits in my panel. For the installation I will need a total of four 220V circuits if I need to run a dedicated circuit to each fan-coil. 3 circuits for the fan-coils and 1 circuit for the outside unit. The fan-coil units only draw less than 1 amp each max. The electrician is telling me that I can not run all three fan-coil units on one 220V circuit because each fan-coil unit has a DC motor in it(code issue). Could someone confirm this for me? Thanks If you have to run a dedicated circuit for each fan, I think you have answered your own question. It sounds like the panel is full and it might be time to install a second panel to handle the additional circuits. Quote Link to comment Share on other sites More sharing options...
jbrown40004 Posted April 30, 2014 Author Report Share Posted April 30, 2014 Thanks Scott, In my post i said "IF I need to run 3 dedicated circuits". So therein is my question. Do I have to run a dedicated circuit for each fan-coil given the circumstances? Quote Link to comment Share on other sites More sharing options...
Scottpat Posted April 30, 2014 Report Share Posted April 30, 2014 I don't know.... I would think that it depends on how much the transformer draws or what is its requirements are. Since you are converting AC to DC everything downstream of the inverter would need to be rated to the inverters specs. You will need a disconnect at each unit and the outside unit. I have never worked or seen this type of system. Quote Link to comment Share on other sites More sharing options...
Marc Posted April 30, 2014 Report Share Posted April 30, 2014 Is there a factory-installed fuse or breaker on each fan coil unit? Is this DC powered blower motor the only electrical load in each fan coil unit? Post a photo of the fan coil nameplate if you can. Marc Quote Link to comment Share on other sites More sharing options...
Jim Katen Posted May 1, 2014 Report Share Posted May 1, 2014 . . . The fan-coil units only draw less than 1 amp each max. The electrician is telling me that I can not run all three fan-coil units on one 220V circuit because each fan-coil unit has a DC motor in it(code issue). . . I'm not familiar with a code section that would limit the number of 1 amp DC motors on a circuit. Would it be possible for you to ask the electrician for the exact section of the code that he thinks prohibits this? Quote Link to comment Share on other sites More sharing options...
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