Invacare TRx Power Positioning System manual Safety Lockout and Limit Switches, Tilt Limit Switch

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8.0 Safety Lockout and Limit Switches

WARNING! The angle at which the limit switches are set is critical to the safe operation of

!the power positioning system. Motion Concepts will not be liable for any injuries or damage sustained when adjustments are made beyond the factory recommended range. These switch- es should only be adjusted and set by a trained Technician.

iImportant: Please refer to the Motion Concepts General TRx Set-up Manual for detailed instructions on setting and adjusting Limit Switches

Drive Lockout (DLO) Limit Switch

All TRx systems with tilt and/or recline functions are equipped with a drive lockout limit switch. This switch prevents the drive motors from operating if the back is positioned beyond a pre-determined angle. The rec- ommended drive lockout angle is 15° to 20° from the vertical. The limit switch should be set to the angle that best meets the overall stability and individual needs of the user, but should not exceed the max- imum 20° angle.

All TRx systems with power elevating seats are also equipped with a drive lockout limit switch. These sys- tems typically use a microswitch to prevent the drive motors from operating once the seat begins to ele- vate. The microswitch should engage the Drive Lockout when the seat actuator has been elevated beyond a recommended 1/2” limit [measured from the seat’s home (lowest) position].

Tilt Limit Switch

All TRx systems, except those using our basic single motor function relay box, can be equipped with a tilt limit switch. The function of this switch is to prevent the back angle from extending beyond a pre-set angle. Ultimately the angle should be set to meet the individual needs of the user. However, the recline angle should never extend beyond a recommended 5° from the horizontal. The limit must also be checked to ensure that with any combination of tilt and recline, there is absolutely no possibility of interference between the back of the TRx system (or any accessories located on the back), and the wheelchair base.

!CAUTION! When setting tilt limits remember to consider the size and location of any personal gear that will be carried on the wheelchair, as it could cause interference with tilt or recline motor functions.

Elevating Seat Lockout Switch

All TRx power elevating seat systems, when combined with tilt and/or recline functions, are equipped with an elevating seat lockout switch. This limit switch prevents the PES actuator from elevating or descending when the system is in a tilted or reclined position. The recommended lockout limit should not exceed a maximum of 8° from the seating system’s original pre-tilt (“home”) position, and it is recommended to be set between 3° and 8°.

Anti-Tipper Latch Limit Switch

Certain powerbases come equipped with anti-tip devices that latch in order to ensure stability during tilt, recline or elevating functions. For these powerbases, our TRx systems are engineered to control and engage the anti-tipper latch through the use of a limit switch. The recommended limit switch settings are determined by the type of power positioning system:

i)Tilt-Only:set switch to engage the anti-tippers when seat angle is at 10° (regardless of pre-tilt angle).

ii)Tilt/Recline & Recline-Only: set switch to engage the anti-tipperswhen the back reclines 10° (from upright)

iii)Power Elevating Seats (PES): set switch to engage the anti-tippers when seat actuator has elevated

beyond a recommended 1/2” limit.

In some instances, an anti-tipper latching system is added to the power base as part of the installation in order to ensure the stability of the power positioning system is maintained.

TRD0000, TRx Owner’s Manual- Rev. 5.0, January 20, 2005