Maintenance - TTI PL Serie Manuel D'instructions

Remote Sensing
The unit has a very low output impedance, but this is inevitably increased by the resistance of the
connecting leads. At high currents, this can result in significant differences between the indicated
source voltage and the actual load voltage, (two 50mΩ connecting leads will drop 0·2V at 2 Amps,
for instance). This problem can be minimised by using short, thick, connecting leads, but where
necessary it can be completely overcome by using the remote sense facility.
This requires the sense terminals to be connected to the output at the load instead of at the
source; remove the two shorting bars and connect the sense terminals directly to the load. To
avoid instability and transient response problems, care must be taken to ensure good coupling
between each output and sense lead. This can be done either by twisting the leads together or by
using coaxially screened cable (sense through the inner). An electrolytic capacitor directly across
the load connection point may also be beneficial.
The voltage drop in each output lead must not exceed 0·5 Volts.
The shorting bars must be re-fitted if the remote sensing facility is not being used. Remote
sensing cannot be used in the tracking or series modes on either output.
Other Considerations
The power supplies generate considerable heat and require a full air cooling flow for correct
operation. Do not obstruct any of the cooling slots in the cover, or block the inflow of air at the
bottom.
Avoid allowing the supply to get damp, and keep away from corrosive fluids.
The Manufacturers or their agents overseas will provide repair for any unit developing a fault.
Where owners wish to undertake their own maintenance work, this should only be done by skilled
personnel in conjunction with the service manual which may be purchased directly from the
Manufacturers or their agents overseas.
Cleaning
If the PSU requires cleaning use a cloth that is only lightly dampened with water or a mild
detergent. Polish the display window with a soft dry cloth.
WARNING! TO AVOID ELECTRIC SHOCK, OR DAMAGE TO THE PSU, NEVER ALLOW
WATER TO GET INSIDE THE CASE. TO AVOID DAMAGE TO THE CASE OR DISPLAY
WINDOW NEVER CLEAN WITH SOLVENTS.
12

Maintenance