- Hewlett-Packard Power Supply User Manual

Installation - 3

Under normal operation, the dc source senses the output voltage at the output terminals on the back

of the unit. External sense terminals are available on the back of the unit that allow the output

voltages to be sensed at the load, compensating for impedance losses in the load wiring. You

cannot remote sense at the optional front panel binding posts.

The output terminal block of the unit is shipped configured for local sensing, with the +S terminal

jumpered to +, and the −S terminal jumpered to −. Remove these jumpers when making your sense

wire connections. The terminal block screws are 6-32 X 3/8 inch.

Sense Leads

The sense leads are part of the dc source's feedback path and must be kept at a low resistance (less

than several ohms) to maintain optimal performance. Connect the sense leads carefully so that they

do not become open-circuited. If the sense leads are left unconnected or become open during

operation, the dc source will regulate at the output terminals, resulting in a 3% to 5% increase in

output over the programmed value. Shorting the sense leads trips the OVP circuit.

NOTE: It is good engineering practice to twist and shield all signal wires to and from the

sense connectors. Connect the shield at the dc source end only. Do not use the

shield as one of the sensing conductors.

-S

+ 240 VDC MAX TO

twisted or

shielded pair

LOAD

remove

sense

jumpers

Figure 3-3. Remote Sense Connections

The overvoltage protection circuit senses voltage near the output terminals, not at the load.

Therefore the signal sensed by the OVP circuit can be significantly higher than the actual voltage