Chassis Dynamometer Safety
Cummins Southern Plains, Ltd.
Chassis Dynamometer Safety
Setting
Up the Truck
Inspection
Running the Truck
Ventilation System
Additional Considerations
Setting up the Truck
Attach the rear safety chain.
 The rear tie-down chain is the first
restraint to be installed, and the last to be
removed.
 Do not wrap the rear tie-down chain
around brake lines or other items that
may be easily damaged.

Setting up the Truck
 Rear
Safety Chain
A keeper to the “boomer” or load tensioner
to keep handle from popping off.
Orange hook is a safety back up in case
tensioner fails.
Setting up the truck (cont.)



The front tie-down straps are the primary
restraints that provide safety in the event of a
problem.
The rear chain prevents forward movements, but
side-to-side movements may occur at the rear of
the vehicle.
Before beginning, know your dyno hood
clearance distance and that a FE is in the area.
Setting up the Truck
Before placing
vehicle on roller,
make sure air to the
facility is turned on.
If no air, truck will
roll off roller and may
hit wall. Rollers have
air applied
brakes/spring
released.
 Picture shows a dent
in the back wall from
a unit that rolled off.

Inspection

Always inspect the tie-down straps and
ratchet mechanisms for wear. Do not use
excessively worn or damaged parts.
On tie down straps; inspect all strap
material and bolts.
Tie down chains: inspect all bolts and keys.
Running the Truck




Always remain in the drivers seat
when conducting a test.
Never allow observers to be in
the room when conducting a
test.
Sensors may be connected to
fluids under pressure, or may
still be hot after a cool-down
period. Use extreme caution
when disconnecting sensors.
Safety glasses and hearing
protection must be worn during a
test.
Running the Truck




Never apply the brakes or turn the steering wheel
while a test is in progress.
Always set the vehicle parking brakes and the
dynamometer roll lock when not executing a test.
Emergency stop button is located on the wallmounted interconnect box. In the event of an
emergency, press the button.
Nobody else should be in area when in operation.
Hole in the rear wall from a
rock dislodge from a tire
during a test run.
Ventilation System



Engine exhaust fumes contain particulate matter,
Carbon Dioxide, and Carbon Monoxide..
Never run the engine or conduct a test without
the proper room ventilation and evacuation for
exhaust fumes.
At least one door of the chassis dyno must be
open during operation of the ventilation system.
Ventilation System

These are different exhaust tubes designed for
different exhaust systems. The curved one in the
right picture is for busses with exhaust out the
top. Larger one in front for RVs. Be careful not to
place the tubes close to housing as it may bubble
the paint on an RV.
A variety of hose extensions should
be available
Additional Considerations
Housekeeping with the hoses on
the swing out rack should be
maintained at all times.
Minimum ladder needed to
take opacity measurements
on stacks is 8 ft.
Static Electricity
The rotation of rubber tires on steel rolls
causes static electricity build-up.
 If the rear tie-down chain is wrapped
directly around the rear axle or frame
cross member, no further grounding
should be necessary.
 In all other cases it will be necessary to
use a grounding clamp attached to the
dyno frame or other suitable connection
point to earth ground.

Fuel Safety





Keep sparks and open flames away from fuel
measurement system and the output of the vent
connection.
Personal protective clothing should be worn to
prevent diesel fuel contact with the skin or eyes.
Only diesel fuel can be used with the SF-602 fuel
measurement system. Other fuels may produce
dangerous vapors. The system is NOT explosion
proof.
The fuel can vent on the side of the cabinet must
be open to a safe place in the atmosphere.
A blocked vent could cause the can to burst or
leak.
Calibration


Calibration arm and
weight (500 lbs.) for
calibrating the sensor on
the absorption unit.
Need two people for this
lift and a cherry picker.
Calibration takes place
once a year.
Need to open pit to
access the mounting
point for the torque arm
onto the absorption unit.
Uses cones and warning
line around the pit to
keep people out.
Additional Safety Notes
Always remove all test lead and exhaust
management devices before removing
straps and chains. This will save you from
driving off with expensive equipment.
 Trip hazards from the test equipment and
leads can be a problem in the dyno room.
Keep main walkway clear as much as
possible.
 Oil and coolant spills are common.
Housekeeping is essential.
