Minisplit power 220v

 about to hookup a ductless minisplit (all refrigerant work done, lines purged
with
nitrogen and vacuumed)

outdoor and indoor units are connected with a 3-wire connection, no problem there

additionally, there is a ground wire between the indoor and outdoor units.

my question is about the 220v connection to the outdoor unit.
the directions show just two hot 110v connections going into outdoor unit
(marked as
terminal block 4 and 5), there is no ground wire from my outdoor 20amp circuit
breaker
box in the diagram.

can that be correct?

in case anyone's interested, it's the fujitsu 9RLQ (page 8 of install manual on
http://www.fujitsugeneral.com/wallmountediaq.htm  - select link for manuals)

 

(marked as

breaker

Sure, although I'd expect there to be a safety ground.

To get 240V in a standard residential situation, you
take two 120 legs, which are tapped from the opposite
sides of the transformer, and run them up
to the appliance "against" each other.

Remember, half your house is supplied by one
of the legs, which is 120V referenced to ground;
the other half uses the other leg, which is
similarly 120V to ground.

But the two legs, when against each other,
are 240 V.

(or 208, but let's not go there).

If you're using an outlt, then a 120V outlet
has one "hot" leg and one neutral (plus the
third position for the safety ground).

A 240V outlet has both legs in it.

In other words, while one leg "pushes", the
other "pulls", thus giving you 240V.



--
_____________________________________________________
Knowledge may be power, but communications is the key
             dannyb@panix.com
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 danny burstein wrote:

elaborate a bit, please.
my speculation bit is that you mean simply to run a ground wire from the metal
case of
the 20amp breaker to the outdoor unit, thus creating a ground connection (?)

corrections welcome.

 

The Safety Ground which is required is even shown in the diagrams you
refer to (Earth Screw marked G) and should be run all the way bck to the
building entry Ground Connection..

As stated by Denny there is no requirement for what is sometimes called
the neutral or ground in US parlence as it is only the centre point of
the 240 volt system to allow running of 120volt devices. There are no
120 volt devices within this A/C Unit.

John G.