Wayne Kerr AP10030, User & Service Manual

Page: 18 / 70

18 Wayne Kerr AP 1kW Power Supplies • Issue 2
be set at least 2 volts above the output voltage normally required. This avoids the
possibility of false tripping.
Resetting Overvoltage Trip
To reset the overvoltage trip, release the ‘output enable’ push button, wait 5 seconds,
then depress the ‘output enable’ push button. If the power supply trips again, check the
OVL setting is in excess of the set output voltage. This may be done by comparing the
displayed OVL setting with the prospective output voltage (i.e. with output not
‘enabled’).
6.3.3 Overtemperature Protection
An overtemperature condition is indicated by ‘OT’ being illuminated in the status
section. The power supply output will shut down. The meters and bargraphs will read
approximately zero and no other LEDs will be lit.
This condition will occur if there has been overheating within the unit, e.g. due to fan
filter blockage, air intake/outlet restrictions or a too high ambient temperature. Refer to
instructions for filter cleaning (see section 9.1.).
Resetting Overtemperature Trip
When the unit has cooled sufficiently, the overtemperature trip can be reset in a similar
manner to the overvoltage trips i.e. releasing and then resetting the ‘output enable’
button. The trips should only be reset when the cause of the overheating has been
removed.
6.3.4 Low A.C. Mains Voltage Protection
If the a.c. mains input falls below approximately 70% of normal, the power supply will
shut down until the normal mains supply is restored (operation at low mains could cause
overheating and/or unreliable operation).
This condition is indicated by the ‘UNREG’ LED being illuminated. The green ‘enabled’
LED will remain lit, the output will be shut down and the meters will read approximately
zero.
N.B. - If the unit is operating with a mains input voltage near to the minimum specified it
is recommended that the mains impedance check be carried out (section 6.5.). If the
impedance is high the power supply may not be receiving adequate supply volts and this
may cause overheating.