625 Table Back Up / Down Function Troubleshooting
This illustration shows only the components that affect the Back up / down function. A detailed description of current flow during this function also appears below.
Back Down Limit Switch
•Back Down will not operate if switch is tripped.
Back Up Limit Switch
•Back Up will not operate if switch is tripped
230 VAC models only
Line voltage (230 VAC) is supplied thru two fuses (located by the IEC inlet) to a transformer that reduces the line voltage to 115 VAC before it reaches the PC Board.
If an over current condition* is detected the PC board will beep and all power functions will be disabled. Release the function button, remove load, then retry function.
*Weight limit exceeded, mechanical binding, etc.
Power to Foot / Hand Control
115 VAC is supplied thru the two primary fuses, F1 and F2, to the transformer on the PC board. F3 fuse protects the transformer.
The transformer reduces the line voltage and supplies 14VAC to the foot/hand control.
Back Up Operation
If the Back Up limit switch is tripped (open), the Back Up function will not operate
When the Back Up function is activated, current (14 VAC) flows thru the up function foot switch (N.O.), then back to the PC board. Circuitry on the PC Board energizes the back motor. F4 fuse protects the back motor.
When the back function is energized, current flows to the actuator motor. When current flows to the actuator, the actuator motor runs and raises the back section.
Actuator motor runs until:
1.Foot/Hand control button is released.
2.Back Up limit switch is tripped.
3.Fuse(s) opens (blows) - Primary, Base Motor, Transformer fuse.
4.Over-current condition is detected.
Back Down Operation
If the Back Down limit switch is tripped (open), the Back Down function will not operate
When the Back Down function is activated, current (14 VAC) flows thru the up function foot switch (N.O.), then back to the PC board. Circuitry on the PC Board energizes the back motor. F4 fuse protects the back motor.
When the back function is energized, current flows to the actuator motor. When current flows to the actuator, the actuator motor runs and lowers the back section.
Actuator motor runs until:
1.Foot/Hand control button is released.
2.Back Down limit switch is tripped.
3.Fuse(s) opens (blows) - Primary, Base Motor, Transformer fuse.
4.Over-current condition is detected.
