Thermo Scientific 902 Operating And Maintenance Manual page 21

Error Notes
Name: Improper model selected.
Er00 Description: Indicates that DIP SW3 has not selected a proper model or can't be accessed properly.
Response: Display shows "Er00" and will not start-up until a proper model is selected. Contact Technical Services.
ErA1
This error condition will prevent peripherals (fans, compressors, etc.) from powering up with the incorrect voltage.
Name: Voltage/Frequency failure
Description: Indicates the measured RMS line voltage did not agree with the logic level sensed by the micros provided by the
ErC1
installed high voltage PCB; or the measured RMS voltage is not within a tolerable range (180 < Vac < 270 for 230VAC unit / 85 <
Vac < 160 for 120VAC unit); or the frequency measured over 10 cycles was not within a tolerable range (55 Hz < Freq < 70 Hz for
60 Hz units / 40 Hz < Freq < 55 Hz for 50 Hz units)
Erd1
Response: This condition is checked at power on reset and if it is active, the unit will NOT power up. The unit will indefinitely
display "Er_1" in the display and continue to monitor the frequency and voltage. Furthermore, the audible alarm will sound. Other
startup error messages may be displayed prior to this message; however, the system will stop the startup sequence for this condi-
ErE1
tion.
ErA1 .. No pulses (zero crossings) detected to determine frequency (50 / 60 Hz)
ErF1 ErC1 .. Frequency detected is below 50 Hz
Erd1 .. Frequency detected is above 60 Hz (possible noise spikes on supply voltage)
ErE1 .. Unit is 230V and the voltage detected is below the low limit (180VRMS)
Erg1
ErF1 .. Unit is 230V and the voltage detected is above the high limit (260VRMS)
Erg1 .. Unit is 120V and the voltage detected is below the low limit (85VRMS)
ErH1 .. Unit is 120V and the voltage detected is above the high limit (160VRMS)
ErH1
Name: Control (Cabinet) Sensor Failure
Description: This condition indicates that the control sensor has failed to produce a valid reading for >12 consecutive reads (~60
seconds).
Er02
Response: The unit will stage both compressors on (if necessary) and the unit will attempt to head to bottom out. If the sensor
recovers, the system will begin to operate normally and respond to the temperature feedback. The remote alarm contacts will
become active. 'Er02' will be added to the main display queue and the last valid cabinet temperature value will not be displayed.
Name: Heat Exchange Sensor Failure
Description: This condition indicates that the heat exchange sensor has failed to produce a valid reading for >12 consecutive
Er03
reads (~60 seconds).
Response: The display will show "Er03" only when the button sequence to read the heat exchange sensor is depressed.
Thermo Scientific
Section 3
Alarms
Model 900 and 5900 Series 3-3