MOVs (Metal Oxide Varistor) and/or diodes will help suppress most electrical feedback from the locking hardware.  Electrical spikes from the locking hardware could cause the on board relay points to burn in the closed position causing the door not to function properly.  In addition the spike could cause the panel to reset and or become non-operational.

PCSC recommends using MOVs and/or diodes on all door locking hardware.  MOVs and diodes can be found at most electronic stores.

(Source: PCSC)