Make sure your battery negative,
Generator Ground, and "Pigtail" ground are tied together and run to the chassis
of the coach. Do not connect the 120V neutral to this point, Place the neutral on
an Isolated buss, [Isolated from ground] Your "pigtail" should be made up of
10/3 SO cord. For further explanation on grounding see my article on Grounding . I would highly recommend that all 120V power
be protected by fuses which would then feed a main lug breaker box even though they
are more difficult for the novice to trouble shoot, use motor rated or time delay such as
FRN sized to the largest motor on board which would be the a/c.
For you people with 24V systems and 12V apparatus, you might
consider a scheme like this or even make up a 12V and a 24V buss and tie your loads to
them, personally I will be using a > 120A 24V Alternator to replace the 120A 12V that
ended up on my unit and an inverter which will run my 20A central a/c.
Remember, you can use [2} 6V
batteries in series to make a 12V in which case in this drawing you would have [8] 6V
batteries. Don’t forget to take into account the loss within the system which can
be as high as 10% in a good inverter.
I still recommend getting a reputable
local electrician to wire your unit for you, a metal skinned coach, improperly wired, can
be lethal and the cost should not be too excessive.
Caution, 24V should not be taken lightly, a study done years
ago determined that under certain conditions, this voltage range can approximate the
signal from the base of your brain to the heart and cause ventricular fribulation. [heart
"locks" up]. Please install battery disconnects if they are not already in and
wear eye protection when connecting batteries. An inexpensive pair of dry leather gloves
can be of help also.
HOURS OF USABLE POWER AT THE FOLLOWING DRAW:
MODEL 31DCM—950 MCA @ 32 DEG. OR 25 AMP
FOR 3.3 HRS., In the drawing above you could draw 50amps @ 24v for 3.3hrs or 7hrs @
1200 watts consumption (1.6hp) with 200 minutes of 50 amp draw for reserve . OR in this
same drawing you could draw 50 amps @ 12v for 3.3hrs. or 3.3hrs @ 600 watts
consumption (.8hp)with 200 minutes of 50 amp draw for reserve . Bear in mind that in
calculating loads, you must know what the battery will produce.
Examples:
AH rating goes like this; A 300AH
battery at the 10hr. rate of discharge will deliver 30mps for 10hrs before the cells drop
to 1.67V ea. Or 10.02V for a 12V battery.
Reserve capacity: Number of minutes it
can be discharged @ 25A @80 F until the cell drops to 1.75Vea. or 10.5V for a 12V
battery.[a reserve capacity of 100 signifies 100min.].
More Later…after we hear comments to better understand areas of
gray for you.
LD Tullis
Tullis Electric
mailto:pas4me@qwest.net
