Instructions

Installation

Mains Operating Voltage

The operating voltage of the instrument is shown on the rear panel. Should it be necessary to

change the operating voltage from 230V to 115V or vice-versa, proceed as follows:

1. Disconnect the instrument from all voltage sources.

2. Remove the 6 screws which hold the case upper to the chassis and lift off, noting the flat

cable connector positions.

3. Remove the 4 screws securing the power supply pcb to the chassis and lift the pcb free.

4. Change the appropriate zero-ohm links beside the transformer on the pcb:

Link LK4 only for 230V operation

Link LK3 and LK5 only for 115V operation

Note that, if the change of operating voltage is accompanied by a change of supply

frequency, optimum common mode rejection of the mains will be achieved by setting the

internal 100/120Hz selection to 100Hz for 50Hz supply and 120Hz for a 60Hz supply.

This is set by the status of link LK2 which is situated immediately below the oscillator

module on the main circuit board. With no shorting link fitted to the pins the frequency is

set to 100Hz; if a shorting link is fitted it is set to 120Hz. The factory setting for 230V

operation is 100Hz and for 115V operation is 120Hz. If LK2 is changed from the factory

setting the unit will need to be recalibrated at the new frequency setting (calibration

settings for 100Hz and 120Hz cannot be held simultaneously).

5. Refit the pcb to the chassis, ensuring all connections (especially safety earth) are remade

as before, and refit the case upper.

6. To comply with safety standard requirements the operating voltage marked on the rear

panel must be changed to clearly show the new voltage setting.

7. Change the fuse to suit the new operating voltage, see below.

Fuse

The correct time-lag fuse must be fitted for the selected operating voltage.

For 230V operation use 125mA (T) 250V HBC.

For 115V operation use 250mA (T) 250V HBC.

Make sure that only fuses with the required rated current and of the specified type are used for

replacement. The use of makeshift fuses and the short-circuiting of fuse holders are prohibited.

Mains Lead

Connect the instrument to the AC supply using the mains lead provided. Should a mains plug be

required for a different mains outlet socket, a suitably rated and approved mains lead set should

be used which is fitted with the required wall plug and an IEC60320 C13 connector for the

instrument end. To determine the minimum current rating of the lead-set for the intended AC

supply, refer to the power rating information on the equipment or in the Specification.

WARNING! THIS INSTRUMENT MUST BE EARTHED

Any interruption of the mains earth conductor inside or outside the instrument will make the

instrument dangerous. Intentional interruption is prohibited.