The model 4383 is an device that is has three sets of relay output contacts. Two sets are normally open and one set is normally closed. When operating voltage is applied, the output contacts
transfer for the full duration of the preset timing period, or until the operating voltage is removed. The model 4383 is protected against high electrical noise as is found in electric transit
cars and locomotive type applications. Both fixed timing and remotely adjustable timing models are available. The polarity of operating voltage does not have to be observed.