nifty TM Series Operating And Safety Instructions Manual page 32

TM Series
Operating & Safety Instructions
The failure signal is generated if either relay fails to respond to the 'safe' cage weigh signal from the
safety micro-switch, either due to a coil or contacts failing or if a contact sticks in place due to
welding. Under either circumstance the 'enable' signal is blocked, instead generating the error
message, illuminating the red LD2. The machine will not operate under this situation. The red error
signal from LD2 requires the board to be changed, as the relays are not serviceable items.
4.5.6 MAINTENANCE
The cage weigh mechanism is supported on maintenance-free precision needle roller bearings for
smooth running and friction-free operation. The accuracy of the entire assembly and in particular the
hysteresis is dependent on these components. Keeping them free of dust and dirt is recommended;
and an occasional application of WD40 to the external faces should keep them mobile and deny the
entry of dust and moisture.
The hysteresis is the amount of load required to be removed before the system re-sets allowing
continued operation.
If the assembly is subjected to any external impact force, typically whilst manoeuvring the machine
under power, or in the case of trailer units, whilst being reversed into position, the cage assembly will
require close inspection. If there is evidence of any deformation in any part of the structure, then the
advice of a Niftylift Service technician should be sought. Physical damage to the assembly is liable to
render the cage weigh system inactive, or to affect the accuracy of the result. Under no circumstance
permit a damaged machine to enter service without performing a thorough inspection and calibration of
the weigh assembly.
For this reason it is not recommended to restrain the machine in transit using strap or chains passed
through or over the cage itself. This is particularly true of the electronic load cell system, which could
be permanently damaged by the application of such excessive external forces. Whilst the mechanical
system could be considered to be more robust in operation, the same restraint forces that could be
generated through ratchet straps and the like, is likely to cause some severe deformation in the
lightweight cage structure. Use only the designated tie-down points on your Niftylift when strapping
the machine down for transport. Failure to observe this instruction could render the machine un-
usable, and a considerable repair bill for the damaged components.
4.5.7 REPLACEMENT
If components are replaced, they must be genuine Niftylift parts. The accuracy and function of the
cage weigh system relies on the like-for-like application of the component parts. A switch from a
similar manufacturer might reverse the contact arrangement and critically affect the function of the
mechanism. Similarly, the accuracy of the sensing circuit relies on the duplication of the contact travel
within the switch itself. Using a non-equivalent component will render the cage weigh system inactive.
Under no circumstances should you permit a machine with a defective cage weigh assembly to enter
service.
If in doubt about the operation or function of your machine, always request the circuit diagram that
goes with the machine serial number. Look at the bottom of the machine serial plate; one of the final
two numbers stamped there will give the electrical circuit for the machine. ('D80000' number, plus the
issue status immediately afterwards: - /01;/02;/03; etc, see Section 1.5 & 1.5a, pages 5/6)
If in doubt, contact the Niftylift Service Department on (44) 01908 223456, Fax: 01908 227460.
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English/USA – 01/10
Issue 06