3300/20 Dual Thrust Position Monitor Bently Nevada

3300/20 Dual Thrust Position Monitor Bently Nevada

Description 

The 3300/20 Dual Thrust Position Monitor provides early warning of thrust bearing failure.  It continuously measures and monitors two independent channels of shaft axial position relative to the axial clearances within the machine.  Ideally, the axial probes are installed to observe the thrust collar directly, so the measurement represents the position of the collar relative to the thrust bearing clearance. Caution Because thrust measurements are made by observing the gap voltage of the proximity probe used as an input, a transducer failure (gap out of range) can be interpreted by the monitor as thrust position movement and result in a false thrust alarm.  For this reason, Bently Nevada LLC. does not recommend the use of a single probe for thrust position applications.  Instead, these applications should use two proximity probes observing the same collar or shaft and configure the monitor as AND voting whereby both transducers must simultaneously reach or exceed their alarm setpoints for the monitor’s alarm relays to actuate.  This 2-out-of-2 voting scheme  (also known as AND voting) provides optimum protection against both false trips and missed trips.  While the 3300/20 monitor can be programmed for either single voting (OR) or dual voting (AND), dual voting is strongly recommended for all thrust position applications.    Caution Probe adjustment and range is critical in this monitor for machinery protection. Improper adjustment of the transducer may prevent the monitor from alarming (no machinery protection). For proper adjustment, follow instructions in the manual.

Specifications 

Inputs Signal: Input Impedance: Sensitivity: Power: Accepts one or two proximity probe signal inputs. 10 k Ω. User-programmable for 200 mV/mil  (8 V/mm) or 100 mV/mil (4 V/mm). Nominal consumption of 1.5 watts.

Spare Relay Module Assemblies 

 (Order the option in parenthesis for ATEX approved spares) 

 81544-01(02) No Relays 81545-01(02) Dual Epoxy Relays 

 81546-01(02) Dual Hermetic Relays 84152-01(02) Quad Relays 

 88984-01(04) Dual Hermetic, Internal Barriers 

 88984-02(05) Dual Epoxy, Internal Barriers 

 88984-03(06) No Relay, Internal Barriers