3M Bair Hugger 775 - Accessing and Exiting Service Modes

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3M™ Bair Hugger™ Warming Unit Model 775 – Service Manual
Warming Unit Power‑On‑Reset
The warming unit automatically performs the following power-on-reset
sequence after you connect the warming unit to a properly grounded power
source (See Figure1):
• Performs all self-test functions.
• Illuminates indicator lights and all pixels in the alphanumeric
displaymomentarily.
• Displays the text “MD 700’s” and the software revision level in the
alphanumericdisplay.
• Sounds the alarm (three low-levelclicks).
• Enters the Standby mode with the high fan setting selected bydefault.
NOTE: The low fan setting indicator light will not illuminate during
powerup.
If the warming unit loses power for less than 1second, the warming unit
software will return the warming unit to the operating mode you selected
prior to the power loss. However, if the warming unit loses power for longer
than 1second, the warming unit software will reset when you restore power.
The warming unit will then enter the Standby mode with the high fan setting
selected bydefault.
Temperature Modes
The warming unit has 4operating modes: Ambient, 32°C, 38°C,43°C.
To select the 32°C, 38°C, 43°C, or Ambient mode, press the corresponding
button. The warming unit will operate within the specified temperature
range, shown in the tablebelow.
TEMPERATURE MODE TEMPERATURE OF DELIVEREDAIR
32°C 32°C ±1.5°C
38°C 38°C ±1.5°C
43°C 43°C ±1.5°C
Ambient
Warming unit will supply air at
roomtemperature
After you select a temperature mode, the following eventsoccur:
• Corresponding temperature indicator lightilluminates.
• Blower operates at selected fanspeed.
• Heater activates except in Ambientmode.
• Temperature mode timer and hour meteractivate.
• Temperature at the blanket-end of the hose appears in the
alphanumericdisplay.
• Temp in Range indicator light illuminates when the temperature at the
blanket end of the hose is within ±1.5°C of the selected setting; this
indicator light does not illuminate in the Ambientmode.
AirflowModes
The warming unit has two preset fan speed settings: a default or high fan
setting ( ) and a reduced or low fan setting ( ). The warming unit will
reset/default to the high fan setting each time the warming unit is powered
up or Standby is selected. The low fan setting ( ) may be preselected while
in Standby prior to selecting the desiredtemperature.
StandbyMode
To place the warming unit in Standby mode, press the Standby button.
When in Standby mode, the following eventsoccur:
• Standby indicator light illuminates.
• Blower and heater are turnedOFF.
• Alphanumeric display deactivates.
• Alarm and fault detection functions remainactive.
• Operating timerpauses.
• Airflow mode resets/defaults to the high fansetting.
FaultConditions
The warming unit software recognizes several nonhazardous fault
conditionsincluding:
• Sensor failures
• Heaterfailures
• Computerfailure
• Software failure
• Keypadfailure
• Power supplyfailure
• Blower motor failure
• Forced over-temperature testfailure
When a fault condition exists, the following eventsoccur:
• Fault indicator light flashes.
• Audible alarmsounds.
• Blower and heater turnoff.
• Fault code appears in the alphanumericdisplay.
• Up to 5fault codes are stored inmemory.
When the audible alarm sounds, press any button on the keypad to silence
it. The warming unit must be unplugged before it can be restarted. See
“Viewing the Fault Code Log” on page 8and the “Fault Code Table” on
page 9for more information about specific faultcodes.
Over‑TemperatureCondition
When an over temperature condition exists, the following eventsoccur:
• Over‑temp indicator light flashes.
• Audible alarmsounds.
• Blower, heater, and operating mode indicator lights automatically
turnoff.
• Fault code appears in the alphanumeric display (see page9).
When the audible alarm sounds, press any button on the keypad to silence
it. The warming unit must be unplugged before it can berestarted.
AlternativeModes
The warming unit has 5 alternative modes that allow access to the service
and calibration utilities of the warming unit (see Figure 2on page 7).
ALTERNATIVE MODES DESCRIPTION
AltMode0 Hour Meter
AltMode1 Calibration
AltMode2 Fault CodeLog
AltMode3 System Information
AltMode4 Over-temperature DetectionTest
The Hour Meter mode displays the cumulative amount of operating time (in
Ambient, 32°C, 38°C, and 43°C modes) the warming unit has been in use.
The time is displayed in whole hoursonly.
The Calibration mode allows a technician to check and adjust the hose
end sensor calibration offset value. This should be done as part of routine
maintenance and after servicing the warming unit or replacing the hose.
The hose end sensor temperature can be altered a maximum of ±3.0°C by
adjusting the calibration offset value. In the Calibration mode, the warming
unit operates in the Ambient temperature mode, and the alphanumeric
display shows the current hose end sensor temperature and calibration
offset with 0.1°C precision.
The Fault Code Log mode sequentially displays the last 5fault codes stored
in system memory. Please refer to the “Fault Code Table” on page 8 for
more information about a particular fault code.
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The System Information mode allows the technician to view important
system information including the firmware, system identification, serial port
baud rate, 5V power supply status, and the control board serialnumber.
The Over‑temperature Detection Test mode allows the user to test the
operation of the independent over-temperature shutdown system.
Accessing the AlternativeModes
To access the alternative modes, you must press the Alternative Mode
button that is located on the front panel of the warming unit but is
unlabeled. Press the center of the BairHugger logo when the instructions
direct you to press the Alternative Modebutton.
TEMP IN RANGE
FAULT
OVER TEMP
STANDBY
AMBIENT
MODEL
775
43 C
MEDIUM
HIGH
TEMPERATURE
AIR FLOW
38 C
LOW
32 C
System
System
Information
AltMode3
Alternative
Mode button
AltMode0
Over‑temperature
Detection
TestAltMode4
Fault
Code Log
AltMode2
Calibration
AltMode1
Figure 2. Location of Alternative Modebutton
To enter one of the alternative modes, press the Alternative Mode button in
combination with one of the operating mode buttons, also located on the
front panel. Figure 2 indicates which keys must be pressed to enter each of
the 5 alternative modes. When the correct combination of keys is pressed,
the display reads “Hold for AltModeX,” where “X” represents the selected
alternativemode.
Exiting an AlternativeMode
Exit the alternative modes by pressing the Alternative Mode button or by
waiting for 60seconds. You will need to access the alternative modes for
several of the service procedures described in thismanual.
Required PreventativeMaintenance
Note: Auto tester must not interrupt the voltage during warming unit on
power reset or an Error 053/054mayresult.
Calibrating the OperatingTemperature
!
Caution: Perform all temperature testing of the warming unit with a
3M Model 22110temperature testunit.
3M assumes no responsibility for the reliability, safety, or performance
of the BairHugger temperature management system if temperature
tests or adjustments are made in any manner other than those described
here. Improper measurement or adjustment of the warming unit’s normal
operating temperature could result in patient exposure to temperatures
outside of the indicated range and may lead to patient injury.
Service frequency
Every 6 months or 500hours of use, or whenever service isperformed.
Tools/equipment
Model 22110 temperature testunit
Calibrated thermocouple temperature monitor
NOTES:
• The Model 22110temperature test unit simulates the operating
characteristics of 3M warming blankets and gowns when used with
BairHugger warming units.
• When using the Model 22110 temperature test unit, take temperature
readings using a calibrated thermometer that can accept a male,
subminiature connector and read a “K” style thermocouple (e.g., a
Fluke Model 52K/J Thermometer). If the test unit connector does not
fit your thermometer, remove the connector from the test unit and
attach a connector that fits your meter. Be certain to observepolarity.
METHOD
Note: If the warming unit has been stored at a temperature lower than
20°C, allow it to reach ambient temperature before beginning the
calibration procedure.
1. Attach the Model 22110 temperature test unit to the end of the
warming unithose.
2. Connect the warming unit to a grounded power source. The
warming unit performs a self-test and automatically proceeds to
Standbymode.
3. Press the Ambient button to place the warming unit in Ambient
mode. Allow the warming unit to run in Ambient mode for at least
ten minutes to equalize the temperature of the warming unit’s
internalcomponents.
NOTE: Verify warming unit is set to high fan setting by ensuring the
indicator light next to the upper fan is illuminated.
4. Press the Alternative Mode button (see Figure 2. Location of
Alternative Mode button on page 7) and the Ambient button
simultaneously for 3 seconds. The warming unit is now in Calibration
mode. In this mode, the warming unit performs the following tasks:
• 32°C and 38°C indicator lights flash indicating they can be used
to adjust the offset value.
• Blower remainson.
• Heater elements remainoff.
•ThetextTMP and the end of hose temperature in °C (0.1°C
resolution) appear in the alphanumeric display.
•ThetextOS and the current calibration offset value (0.1°C
resolution) appear in the alphanumeric display.
5. Compare the temperature shown on the alphanumeric display and the
temperature shown on the thermocouple monitor.
• If the temperatures match, no adjustment is necessary, press
the Alternative Mode button to return the warming unit to
Standby mode.
• If the temperatures do not match, adjust the warming unit
displayed temperature:
a. Press the 32°C button to decrease the temperature or the
38°C button to increase the temperature by 0.1°C. You can
adjust the temperature of the warming unit a maximum
of±3°C.
b. Continue to press the 32°C or 38°C button(s) until the
temperature in the alphanumeric display matches the
temperature on the thermocouple monitor as close
aspossible.
c. Press the Alternative Mode button to store the calibration
offset value and return the warming unit to Standbymode.
Note: If it is necessary to enter an offset value greater than ±3°C, there may
be a defect in the warming unit hose end sensor. Remove warming unit from
service until a new hose assembly can besubstituted.
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