3M Bair Hugger 675 Service Manual Download

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English / 34-8720-2487-1

Standby Mode

The

Standby

mode is a temporary state that lasts a maximum of 10 seconds and the

Bair Logo

is displayed on the LCD screen.

To enter

Standby

mode, press the

Power

button from Sleep mode.

To exit

Standby

mode, either: a) Press the

Bair Logo

for three seconds to enter

Diagnostic

mode; or b) Wait 10 seconds and the unit will go into

Sleep

mode.

Sleep Mode

During

Sleep

mode, the warming unit is idle and awaiting user activation. When in

Sleep

mode the following events occur:

• System timer remains active.
• The LCD goes blank.
• The

Power

indicator illuminates amber.

To enter

Sleep

mode, press the

Power

button from either the

Diagnostic

mode or

Operation

mode.

To exit

Sleep

mode, either: a) Press the

Power

to enter

Standby

mode; or, b) Press a

temperature button to enter

Operation

mode.

Fault Conditions

The Model 675 warming unit’s software recognizes several nonhazardous fault
conditions including:

• Sensor failures.
• Microprocessor failures.
• Software failures.
• Keypad failures.
• Power supply failure.
• Temperature out of range.

When a fault condition exists, the following events occur:

• Blower turns off.
• Heater turns off.
• Audible alarm sounds.
• Fault wrench appears on LCD screen.

• Fault code appears on LCD screen.
• Up to 20 fault codes are stored in memory.

Silence Alarm/Reset Unit

• When the audible alarm sounds, press the

Power

button on the keypad to

silence it.

• The warming unit must be unplugged before it can be used. See

“Viewing the

Fault Code Log”

and the

“Fault Code Table”

for more information about specific

fault codes.

Over-Temperature Condition

An independent electronic thermal cutoff safety circuit shuts the heater off to ensure

the hose end air remains below 56°C if an over-temperature condition is detected. An

over-temperature condition occurs when one of the following is detected:

1. The independent thermal cutoff safety circuit senses the air exiting the unit

exceeds 53°C [±3°C].

2. The temperature exceeds 47°C for 30 seconds.
3. The temperature is 3°C above set point for 3 minutes.

When an over-temperature condition exists, the following events occur:

• Over-temperature indicator and fault

condition wrench alternate displaying

in the LCD screen.

• Audible alarm sounds.
• Blower and heater turn off.

The warming unit must be unplugged before it can be used.

Under-Temperature Condition

An under-temperature condition occurs when the warming unit detects the

temperature set point has not been reached or maintained during use. It occurs when
the temperature is less than 3°C below the selected temperature for 3 minutes.
When an under-temperature condition exists, the following events occur:

1. Under-temperature indicator and fault

condition wrench alternate displaying

in the LCD screen.

2. Audible alarm sounds.
3. Blower and heater turn off.

The warming unit must be unplugged before it can be used.

Diagnostic Mode

The Bair Hugger Model 675 has a diagnostic mode that allows access to the service
and calibration utilities of the unit. You will need to access the diagnostic menu for

several service procedures described in this manual.

To access

Diagnostic

mode, press and hold the

Diagnostic Mode

button (i.e. Bair

Logo) for three seconds. The

Diagnostic Mode, Ambient, 32, 38,

and

Power

buttons

are used to access