FITTING AS 1645629 - Caterpillar

Single Horsepower Test Procedure
Illustration 1 shows a single power "dog leg" torque curve.
Illustration 1. Typical single power "dog leg" torque curve. Engine speed in rpm is on the horizontal axis. Torque is on the vertical axis. Point 1 is the rated test point.Point 2 is the peak torque test point.Point 3 is the advertised speed and power. The advertised power is no longer checked directly and can no longer be referenced using test cell history in the Technical Marketing Information (TMI) system. The 2100 rpm point and the 1400 rpm point are available through the TMI system as usual.Illustrations 1 and 2 show a 1900 rpm advertised rated speed and a 2100 rpm "dog leg" speed. All of the listed motor grader arrangements have this configuration. The D300E and D250E Articulated Trucks have a 2200 rpm advertised rated speed and a 2400 rpm "dog leg".
The "dog leg" point (2100 rpm for motor graders or 2400 rpm for articulated trucks) should be used when addressing low power questions from customers.
Dual Horsepower Test Procedure
Illustration 2 shows a typical dual power "dog leg" torque curve.
Illustration 2. Typical dual power "dog leg" torque curve. Engine speed in rpm is on the horizontal axis. Torque is on the vertical axis.Point 1 is the high power rated test point.Point 2 is the high power peak torque test point.Point 3 is the low power rated test point.Point 4 is the low power peak torque test point and is not tested.Points 1 and 3 are available in the test cell history portion of the TMI system.
The rated test power for the high power test is a LOWER value than the rated test power for the low power specification.The easiest way to identify the high and low power specifications is to look at the advertised power. The higher advertised power is the high power specification.
When resetting a "dog leg" engine, the same procedures used on a "normal" should be used with the following exception:
The "rated" speed for the purposes of reset should be the "dog leg" speed (2100 rpm for motor graders and 2400 rpm for articulated trucks). The continuity light should turn on at 20 to 30 rpm above the rated speed.