Lake Shore Model 642 Electromagnet Power Supply User’s Manual
4-8
Operation
4.12 MAGNET
WATER
The Model 642 provides power to control an external magnet water solenoid control valve. The setup of the valve
control is available in the
Magnet Water
menu. The four menu selections are
Auto, On, Off, and Disabled
, with
Auto
being the default setting.
In the
Auto
mode, the water valve will be energized when the power in the magnet exceeds 100 W. When the power
drops below 100 W, the valve will remain energized for an additional minute to remove any residual heat build-up.
In the
On
mode, the valve will be energized whenever the power supply is on. This feature can be used when the system
is first installed to purge air from the water lines and magnet. It can also be used to turn on the water in advance of a test
to bring the magnet temperature to equilibrium. The
Off
menu selection can be used to turn it off.
In the
Disabled
mode, the Model 642 assumes that no valve is installed and the line for Magnet Water status will not be
displayed.
The magnet water flow switch is monitored whenever the water valve is energized. It is also monitored continuously
when in Disabled mode to allow the use of a flow switch even when no water valve is used. If no flow switch or water
valve is present, then a jumper must be installed across the flow switch contacts for proper operation.
4.13 INTERNAL
WATER
The Model 642 provides power to control an external water solenoid control valve to control the cooling water for the
power supply. The setup of the valve control is available in the
Internal Water
menu. The four menu selections are
Auto, On, Off, and Disabled
, with
Disabled
being the default setting.
In the
Auto
mode, the water valve will be energized when the power in the internal power devices exceeds 100 W. When
the power drops below 100 W, the valve will remain energized for an additional minute to remove any residual heat
build-up.
In the
On
mode, the valve will be energized whenever the power supply is on. This feature can also be used when the
Model 642 is first installed to purge air from the lines. The
Off
menu selection can be used to turn it off.
In the
Disabled
mode, the Model 642 assumes that no valve is installed and the line for Internal Water status will not be
displayed.
The internal water flow switch is monitored whenever the water valve is energized. It is also monitored continuously
when in Disabled mode to allow the use of a flow switch even when no water valve is used. If no flow switch or water
valve is present, then a jumper must be installed across the flow switch contacts for proper operation.
4.14 ERROR STATUS DISPLAY
Error messages appear in the center of the instrument display when a problem is identified during operation. The Fault
LED will also light to indicate error conditions, blinking for operational errors, on continuously for instrument hardware
errors. Refer to Paragraph 7.6 for a listing of all the error conditions. When an error condition occurs, the name of the
error is shown in the display alternately with “Press Status Key for More Info.” Pressing the
Status
key will bring up a
screen that will show an extended description of the error.
To enter the error status display press
Status
while in the main display. A screen similar to the one shown below
appears. This screen will differ depending on the error that is being displayed. If there are no errors to report, the display
will show “No errors reported.” The following example shows the description for “External Current Program Error”.
Cannot set external current program mode.
Set programming voltage to 0 V or change to
internal program mode.
