Lakeshore Learning Materials 622 Manual de usuario descargar pdf (Pagina 60)

Lake Shore Model 620/622/623/647 Magnet Power Supply User’s Manual

Error Messages & Troubleshooting

5-2

No delay is allowed (CAL AND ID switch 7 OFF,

down) and multiple MPS operation (CAL AND ID

switch 4 ON, up) must be selected. After the load

discharges, turn OFF all units to reset. The MPS

displays the OVP error message:

+0.001V

**REMOTE INH.**

OVERVOLTAGE PROTECTION:

FAULT OR RI DETECTED.

OVP IS ENABLED AND

OUTPUTS ARE DESABLED

LOAD MUST BE DISCHARGED

AND ALL UNITS TURNED

OFF TO RESET.

OUTPUTS: *

+1.999A

Overvoltage Protection (OVP) Circuit Activated

If the voltage across the MPS output terminals

rises above ±40 volts, the output over voltage

protection (OVP) circuit activates. The MPS also

may activate the OVP circuit in response to faults.

Upon activation, the OVP circuit uses thyristors to

crowbar the output voltage to between 1 and 1.3

volts until magnet current reaches zero. If this

occurs, change the output current setting to zero.

If the MPS detects OVP activity on power up

(output current greater than ±1 A), it turns ON the

front panel Fault annunciator, closes FLT contacts,

and sounds the alarm twice per second. When the

MPS detects the fault, it closes the FLT contacts to

indicate a fault, sounds the alarm once per

second, and displays:

+0.001V

**OVER VOLTAGE**

OVERVOLTAGE PROTECTION:

THE OUTPUT CURRENT SET-

TING IS FORCED TO ZERO.

OVP IS ACTIVE UNTIL THE

OUTPUT CURRENT FALLS

BELOW 1 A.

OUTPUTS: *

+1.999A

When output current falls below 1 A, the MPS

turns OFF the front panel Fault annunciator and

alarm, and opens the FLT contacts. When the

MPS detects no OVP activity, the Normal Display

appears.

The MPS continues to display OVP and sounds

the alarm until the user enters new output settings,

then turns them OFF. This latching action informs

the user of OVP activity. The MPS opens the FLT

contacts upon detecting OVP inactivity.

Level Alarm Reached

A unique level probe zero reference feature allows

the user to define the current liquid level reading

as the “zero reference” and reads levels above or

below that reference. If turned ON, the software

level alarm notifies the user if the continuously

variable liquid level reaches the set point. The

MPS closes the FLT contacts to indicate the fault,

sounds the alarm about once per second, and

displays:

LIQUID HELIUM LEVEL:

¤ READING

UNITS

NEXT RDG

PERIOD

ALARM

ZERO REF

CALIBRATE PROBE

OUTPUTS: *

+1.999A

: <OFF>

:in (E)

:00:16

:01:00

:+ 14.5 <ON>

:+ 0.0<OFF>

LVL: +14.4 in

FLD: +63.48 kG

+0.001V

**LEVEL ALARM**

The alarm sounds until the level alarm is turned OFF.

When it is turned OFF (or disabled), the MPS opens

the FLT contacts and silences the alarm.

Low AC (LO AC) Detected

If the AC line falls below 80% of the nominal line

selected, the MPS enters AC Loss Mode. If this occurs

on power up, the MPS turns off the front panel circuit

breaker and displays:

+0.001V

**LOW AC LINE**

OUTPUTS: *

+1.999A

THE UNIT WILL BE TURNED

OFF TO AVOID DAMAGE.

VERIFY AC INPUT SETTING

LO AC INPUT

LINE FAULT:

This indicates that the AC source does not match the

line voltage listed on the rear panel.

Upon utility loss during normal operation of a single

MPS with a charged load, the MPS disables utility input

circuitry and uses the load as an energy source. It

turns OFF the front panel Power annunciator and turns

ON the front panel Fault annunciator. It closes the FLT

contacts to indicate a fault and sounds the alarm about

once per second. The MPS sets output voltage

compliance to the level required to maintain operation

and continuously monitors output current. If the utility

recovers, the MPS enters Remote Inhibit Mode and

forces output settings to 0 amps and 1 volt. If the utility

does not recover, the MPS activates the output OVP

circuit and turns OFF the front panel circuit breaker

when the output current drops below 10 amps. Upon

power down, the MPS enters AC Loss Mode.

NOTE: A utility loss while the MPS returns energy from

a charged load to the utility presents no hazard to

personnel working on the utility circuit. The MPS is not

a UPS. It uses the utility voltage wave form to draw

energy from the utility with a sinusoidal current and

return energy to the utility with a sinusoidal current. If

there is no utility reference signal, the MPS disables

utility input circuitry and uses the load for energy.

If utility loss occurs during normal operation in a

multiple MPS configuration, the MPS detecting the

utility loss initiates Multiple MPS Remote Inhibit Mode

by closing the FLT contacts and turning off the front

panel circuit breaker. Then the remaining MPS units

enter Multiple MPS Remote Inhibit Mode.

1 2 ... 55 56 57 58 59 60 61 62 63 64 65 ... 89 90

Comentarios a estos manuales

Sin comentarios

Lakeshore Learning Materials 622 Manual de usuario Pagina 60

Comentarios a estos manuales

Relacionado con productos y manuales para De medición, control y control Lakeshore Learning Materials 622