Section 1
OM6636-B-00
12 February 2015
1-3
Figure 1-2: Rear View
1.4.
REAR PANEL CONNECTORS AND CONTROLS
The rear panel connectors and controls are illustrated in Figure 1-2. They include power entry,
resistor terminals and guard/ground terminals.
1.4.1.
Line Input Connector
The Line input connector is a combination standard male 3-prong AC connector, power
ON/OFF switch and fused line input voltage selector. The line input voltage selector
consists of a four-position selector and a fuse holder. The selector allows switching for
100 VAC, 120 VAC, 220 VAC and 240 VAC. A ½ ampere time delay fuse is provided for
100/120 VAC operation and a ¼ ampere time delay fuse is provided for 220/240 VAC
operation.
1.4.2.
Resistor Terminals
There are a set of two terminal input/outputs for each installed resistance element. Each set
consists of two type N connectors labelled with the nominal value of each of the standard
resistors. The ‘SOURCE’ terminal is to be connected to the voltage source and the
‘OUTPUT’ terminal is to be connected to the input of the measuring circuit of the resistance
measuring device.
1.4.3.
Guard Terminal
The GUARD terminal consists of a four way white binding post. The GUARD terminal is
connected to the isothermal chamber, which contains the standard resistors. This chamber
is isolated from chassis ground and may be linked to the chassis ground terminal with the
link supplied.
1.4.4.
Chassis Ground Terminal
The CHASSIS GND terminal consists of a four way green binding post. The CHASSIS
GND terminal is bonded to the chassis of the model 6636 and to the power ground of the
line input connector.
