Fluke 8842a instruction manual Option -09 True RMS AC

Option –09 True RMS AC

INTRODUCTION

809-1. INTRODUCTION

The True RMS AC option gives the 8842A the ability to make ac voltage and current measurements. The ac functions are selected with the front panel VAC and mA AC buttons, or by remote commands if the IEEE-488 Interface option is installed. Specifications for Option -09 are shown in Section 1, Table 1-1.

809-2. INSTALLATION

The True RMS AC option is contained on a single, easy-to-install printed circuited assembly (PCA). To install the option, proceed as follows:

WARNING

TO AVOID ELECTRIC SHOCK, DISCONNECT THE POWER

CORD AND TEST LEADS BEFORE REMOVING THE

INSTRUMENT CASE.

1.Remove the grounding screw from the bottom of the case and remove the two rear panel mounting screws (Figure 809-1A).

2.Holding the front panel, slide the case and rear bezel off of the chassis (Figure 809-1B). (At this point, the rear bezel is not secured to the case.)

3.Holding the True RMS AC PCA slightly above the chassis, component side down, connect the the ribbon cable from the True RMS AC PCA to the Main PCA and latch it in place. (See Figure 809-1C and D.)

4.Connect the red lead from the True RMS AC PCA to stud W301 on the Main PCA. (See Figure 809-1C.) The stud is located next to the forward end of the FRONT/REAR switch.

5.Make sure the heads of the four plastic latches are in the extended position. Guide the PCA into the 4 circuit board supports.

6.Fasten the True RMS AC PCA to the chassis by pressing the four nylon latches into the mounting supports on the chassis. (See Figure 809-1E.)

7.Reinstall the cover and rear bezel on the chassis and attach the two rear panel mounting screws.

8.Attach the grounding screw to the bottom of the case.

WARNING

TO AVOID ELECTRIC SHOCK, ENSURE THE GROUNDING

SCREW IS FIRMLY ATTACHED TO THE CASE BOTTOM.

9.Calibrate the VAC voltage and mA AC functions according to the calibration instructions given in the Maintenance section.

809-3