products

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.

Ordering Information

Dual Thrust Position Monitor
3300/20-AXX-BXX-CXX-DXX-EXX
Option Descriptions

A: Full-scale Range Option
0 1 25-0-25 mils
0 2 30-0-30 mils
0 3 40-0-40 mils
0 5 50-0-50 mils
0 6 75-0-75 mils
1 1 0.5-0-0.5 mm
1 2 1.0-0-1.0 mm
1 3 2.0-0-2.0 mm

B: Transducer Input Option
0 1 3300 or 7200 Proximitor® systems, 200 mV/mil (Ranges 01, 02, 03, 11, and 12 only.)
0 2 7200 11 mm (not 3300XL)
Proximitor system, 100 mV/mil
0 3 7200 14 mm or 3300 HTPS
Proximitor systems, 100mV/mil
0 4 3000 Proximitor® 200 mV/mil
(Transducer Output Voltage in power supply must be set for – 18 Vdc or use power conver-ter. Ranges 01 and 11 only.)
0 5 3300XL NSv and 3300 RAM Proximitor Sensor, 200 mV/mil (Ranges 01 and 11 only).

C: Alarm Relay Option
0 0 No Relays
0 1 Epoxy-sealed
0 2 Hermetically-sealed
0 3 Quad Relay (Epoxy-sealed only)
0 4 Spare Monitor-No SIM/SIRM

D: Agency Approval Option
0 0 Not required
0 1 CSA/NRTL/C
0 2 ATEX self certification

E: Safety Barrier Option
0 0 None
0 1 External
0 2 Internal