Otis 219HT Armature Re-insulation & Maintenance (ARM)

The 219HT machine is more sensitive to age deterioration due to the absence of top sticks above the coils in the lamination slots. The close proximity of the coil to the top of the slot allows for failure as the insulation surrounding each coil begins to deteriorate combined with the accumulation of carbon dust & debris. ARM is tailored to deep clean the external portion of the armature laminations thus removing the buildup of carbon dust, debris and loose insulation that has accumulated over the years of operation.

Elevator contractor will LOTO and remove the top half of the machine exposing half of

• Elevator contractor will LOTO and remove the top half of the machine exposing half of the armature.  Using a HT brake picking tool to manually rotate the armature when needed.  This tool alleviates the need to hang the car thus reducing costs.
• EMR will begin with testing the armature, field coils, interpoles and the brush assembly.  The testing evaluation will be recorded and presented to the customer along with other recommendations found to be needed.
• Cleansing the armature will begin and during this exercise a resistance to ground test will be periodically checked for improvement.  Caveat; if resistance to ground values do not improve to a susceptible level the customer will be notified and given recommendations towards a different course of action.
• The field coils & interpoles will be cleaned and a Black Class — F polyurethane spray epoxy applied to the field coils (pending the condition of the external insulation).
• Apply a Black Class — F polyurethane spray epoxy to the armature in multiple layers to build a uniform barrier while the armature is rotating slowly via tug.  Caveat: this does not guarantee against a failure due to age or internal wire insulation failure, what re-insulating externally does to the field coils and armature once cleaned is help keep out the carbon dust and small particulates which has the proven potential to extend the life of the fields & armature.