Thetford N500 Series Installation Manual - Manual (Page 7)

Installation Manual 7
Put the AC power cord into a grounded three-prong receptacle:
- Make sure the receptacle is positioned within easy reach of
the lower intake vent.
- Make sure the power cord does not touch the burner cover,
the flue pipe, or any hot component that could damage the
insulation of the power cord.
Connect the 12 volt DC supply (models N400.3 and
N500.3):
As the distance from the vehicle battery to the refrigerator
increases, the correct AWG wire size and fuse size also
increases. If the wire size is too small for the distance, a
voltage drop occurs. The voltage drop decreases the output of
the system heater and causes poor cooling performance.
1. Find the correct min. wire size and the max. fuse size to use:
WARNING: Use only the recommended wire and fuse
size.
- If the distance is 0 - 20 feet, use a minimum of 10 AWG wire
and a 30 amp max. fuse.
- If the distance is over 20 feet, use a minimum of 8 AWG wire
size and a 40 amp max. fuse.
- If the wire is larger than the min. size, use the correct fuse
per RVIA A119.2 standard or local codes.
The wire connections must be clean, tight and free of corrosion.
If any of these items are not correct:
- A voltage drop to the refrigerator will occur.
- The voltage drop will reduce the cooling performance of the
refrigerator.
The terminals for connecting the DC power supply are marked
positive (+) and negative (-) on the terminal block of the refrig-
erator. Make sure that:
- Each DC power supply wire is attached to the correct
polarity terminal.
- The chassis or the vehicle frame is not used as one of the
conductors.
- The DC power supply wires including the fuses are routed
directly from the battery to the refrigerator.
2. Connect the D.C. power supply wires:
- Attach a 1/4 inch Quick Connect terminal to each DC power
supply wire.
- Push each power wire onto the terminal block [1] at the rear
of the refrigerator (See Art00975).
- Make sure each DC power supply wire is on the correct
polarity terminal.
Connect the 12 volts DC supply (model N510.3):
As the distance from the vehicle battery to the refrigerator
increases, the correct AWG wire size and fuse size also
increases. If the wire size is too small for the distance, a
voltage drop occurs. The voltage drop decreases the output of
the system heater and causes poor cooling performance.
1. Determine the min. wire size and the max. fuse size to use:
WARNING: If you use an incorrect wire size and/or fuse
size, electrical fire can result.
- On 2-way models, use a minimum of 18 AWG wire and a
maximum 6 Amp fuse.
- On 3-way models, measure the distance from the vehicle
battery to the refrigerator.
- If the distance is 0 - 20 feet, use a minimum of 10 AWG
wire and a maximum 30 Amp fuse.
- If the distance is over 20 feet, use a minimum of 8 AWG
wire and a maximum 40 Amp fuse.
- If the wire size is larger than the min. size, use the correct
fuse per RVIA A119.2 standard or local codes.
2. Install a fuse in DC power supply wires between the battery
and the refrigerator:
- Put fuse as close to the battery as possible.
3. Connect the DC power supply wires:
- Attach a 1/4 inch Quick Connect terminal to each DC power
supply wire.
NOTE: Do not use the chassis of the refrigerator or the
vehicle frame as one of the conductors. Attach the DC
power supply wires only to the battery and the power board
[1] of the refrigerator.
- Push the positive DC power wire onto the power board
terminal that is marked 12VDC.
- Push the DC ground wire onto the power board terminal
that is marked 12V GND1.
- Make sure each DC power supply wire is on the correct
polarity terminal.