230 Universal Procedures Chair Back Up / Down Function Troubleshooting
This illustration shows only the components that affect the Back Up / Down function.
•If Power Light is ON, proper voltage is present at PC Board.
•If Power Light is OFF, refer to Page A-2 for troubleshooting.
•Black and white wires supply 48-54 VAC to power the Base and Back actuators
On models w/ rotational base, the Main System Transformer connections are supplied thru the Rotational Base PC Board (not shown).
Is There Power To The Chair?
When voltage is present at the PC board, the power light is illuminated. Refer to:Power ToThe Chair for description of current flow to the PC board.
Power To Foot / Hand Controls
Circuitry on the PC board supplies 8-10 VAC to the hand / foot control connection ports.
Back Up Operation
When the Back Up function is activated, current flows thru the hand / foot control, back to the PC board. Circuitry on the PC Board supplies approximately 48 VDC to the back actuator motor.
The actuator motor runs and raises the back section.
The PC board continuously monitors the Back Up limit switch (mounted inside the actuator) and the Back position sensor*.
If the Back Up limit switch is tripped (open), the Back Up function will not operate.
If the Back position sensor detects that the back section has reached its upper limit, the Back Up function will not operate.
Actuator Motor runs until
1.Hand / foot control button is released.
2.Back Up limit switch is tripped.
3.Emergency Stop button* is pressed.
4.Position Sensor* malfunction.
5.Overcurrent protection tripped.
6.Software time-out limit is reached, approximately 30 seconds.
* Midmark models only. This feature is not available on Ritter models
Back Down Operation
When the Back Down function is activated, current flows thru the hand / foot control, back to the PC board. Circuitry on the PC Board supplies approximately 44 VDC to the back actuator motor.
The actuator motor runs and lowers the back section.
The PC board continuously monitors the Back Down limit switch (mounted inside the actuator) and the Back position sensor*.
If the Back Down limit switch is tripped (open), the Back Down function will not operate.
If the Back position sensor detects that the chair is in a potential crash position, or that the back section has reached its lower limit, the Back Down function will not operate.
Actuator Motor runs until:
1.Hand / foot control button is released.
2.Back Down limit switch is tripped.
3.Emergency Stop button* is pressed.
4.Crash Avoidance System* activated.
5.Position Sensor* malfunction.
6.Overcurrent protection tripped.
7.Software time-out limit is reached, approximately 30 seconds.
* Midmark models only. This feature is not available on Ritter models
No Back Up or Back Down
1.Loose / Damaged Wire Connections - Back Actuator, Back Up/Down Limit Switches, hand/foot control ports, black and white wires between main system transformer and PC board
2.Hand / Foot Control Refer to: Hand and Foot Controls
3.Back Actuator Refer to: Back Actuator
4.Main PC Board Refer to: Main PC Board
No Back Up, Back Down OK
1.Loose / Damaged Wire Connections - Hand/Foot Control and Back Up Limit Switch
2.Hand / Foot Control Refer to:Hand and Foot Controls
3.Back Actuator Refer to: Back Actuator
4.Main PC Board Refer to: Main PC Board
No Back Down, Back Up OK, All other chair functions OK
1.Loose / Damaged Wire Connections - Hand/Foot Control and Back Down Limit Switch
2.Hand / Foot Control Refer to: Hand and Foot Controls
3.Back Actuator Refer to: Back Actuator
4.Main PC Board Refer to: Main PC Board
Back drifts down
1.Back Actuator Refer to: Back Actuator
Noisy operation, Grinding, squeaking, etc
1.Back Actuator Refer to: Back Actuator
Moves slowly and/or Will not lift patient
1.Did patient exceed 450 lb. weight limit? Inform staff that max. patient weight is 450 lbs. Refer to:Specifications
2.Low voltage to chair
| Required voltage: | |
|---|---|
|
115 VAC setting |
115 +10% VAC |
|
230 VAC setting |
230 +10% VAC |
3.Back Actuator Refer to: Back Actuator
