Install Manual
Diesel Fuel Systems
Installation Guidelines for Protector Diesel Generators 17
Section 4: Diesel Fuel Systems
General Information
Because  diesel  fuels  are  less  volatile  than  gasoline  or
gaseous  fuels,  they  are  sometimes  considered  safer.
Due to this perception, careless installation practices can
occur which may lead to serious problems with generator
set performance and reliability.
Periodically inspect and test the system to verify all com-
ponents remain in good working order.
Diesel Fuel Base Tank
See Figure 4-1. Units provided are typically mounted on
their own base/fuel tank. These are plumbed at the fac-
tory. Tank construction is typically double-wall. The base
tank is the main fuel tank and incorporates the following
items: 
Figure 4-1. Typical Integrated Diesel Fuel Base Tank
NOTE:  Some  fill  lines  are  equipped  with  overflow  con-
tainment.
Some applications require extending the vent line outside
of an enclosure or to outside air along with adequate spill
containment.
Diesel Fuel Recommendations
IMPORTANT NOTE: DO NOT use home heating oil or
bio-diesel fuel.
Use  No.  2D  diesel  fuel  when  temperatures  are  above
freezing.  When  temperatures  are  below  freezing,  blend
No. 1D diesel fuel and No. 2D diesel fuel together for a
climate adjusted fuel ratio. 
Diesel fuel must also meet the following requirements:
• Sulfur content of 15 parts per million (ppm) maximum.
• Minimum Cetane index of 40.
NOTE:  Low  ambient  temperatures  as  well  as  engine
operation  at  high  altitudes  may  require  the  use  of  fuels
with higher Cetane ratings.
Allow at least 5% of tank capacity for fuel expansion. DO
NOT OVERFILL!
Fuel Maintenance
Diesel  fuel  must  be  treated  for  long  term  storage.  Use
approved  fuel  additive  and  water  abatement  material.
Test  stored  fuel  every  90  days  and  add  treatment  as
required.  Periodically  inspect  and  dry  abatement  as
needed. 
001750
A B C A
FGHJHK
E
D
A Emergency vent—on main tank and rupture basin
B Fuel fill
C Vent
D Fuel return line—from engine; sometimes supplied 
with a check valve
E Fuel supply line—to engine fuel pump; includes in-line 
check valve
F Stub-up area
G Rupture basin leak detector
H Baffle
J Leak containment area
K Fuel level sensor—electrical, mechanical, or both










