Bently Nevada 1900/25 Specifications

1900/25 Vibration Monitor

IN/SEC

MM/SEC

OK ALERT DANGER BYPASS

DISPLAY MODE

NORMAL

ALERT

LEVEL

DANGER

LEVEL

ALERT

ADJUST

DANGER

ADJUST

RESET

BUFFERED

TRANSDUCER

1

0 1 2 3 4 5 6

N

ORMAL

BYPASS

RELAY MODE

ALERT & DANGER

TIME DELAY

00 3 SECONDS

01 5 SECONDS

10 10 SECONDS

11 15 SECONDS

ALERT RELAY

DRIVE CONDITIONS

00 ALERT

01 ALERT OR

NOT OK 10 NOT OK

11 DANGER

SELF TEST

0 OFF

1 ON

UNITS

0 ENGLISH

1 METRIC

MADE IN USA

BENTLY
NEVADA

VIBRATION MONITOR

Description

The 1900/25 is a single-channel, stand-alone, locally mounted vibration monitor.
It provides a built-in Transducer Interface Module (TIM) for connectivity with our
Trendmaster® 2000 system and allows the user to apply machinery protection
capabilities to all (or selected) seismic vibration points of their Trendmaster 2000
system. It can also be used independently of the Trendmaster 2000 system as a
stand-alone machinery protection device, suitable for general-purpose or some
essential machinery. The 1900/25 accepts a single transducer input from
compatible Trendmaster 2000 accelerometers, conditions the signal into peak
velocity units, and provides local display and status indication as well as alarm
relay contact outputs for connection to an external annunciator.

Note: If your application calls for a 4-20 mA interface in addition to the relays supplied with the
1900/25, consider the use of Bently Nevada’s 1900/27 monitor instead (consult part number
141486-01 for details).

Caution
If housing measurements are being made for overall protection of the machine,
thought should be given to the usefulness of the measurement for each
application. Most common machine malfunctions (imbalance, misalignment, etc.)
originate at the rotor and cause an increase (or at least a change) in rotor
vibration. In order for any housing measurement alone to be effective for overall
machine protection, a significant amount of rotor vibration must be faithfully
transmitted to the bearing housing or machine casing, or more specifically, to
the mounting location of the transducer.

In addition, care should be exercised in the physical installation of the
transducer. Improper installation can result in a decrease of the transducer
amplitude and frequency response and/or the generation of signals, which do
not represent actual machine vibration.

Upon request, we can provide engineering services to determine the
appropriateness of housing measurements for the machine in question and/or
to provide installation assistance.
.

Specifications and Ordering Information

Part Number 141485-01

Rev. D (03/07)

Page 1 of 8

Specifications

Inputs

Compatible
transducers

Bently Nevada 200150 and
190520 Accelerometers.

Input Sensitivity

100 mv/g

Maximum
acceleration

20 g peak

Maximum
differential
input voltage

4 volts peak to peak

Power

AC/HDC Power
Version

Signal Conditioning

Monitor Full-scale:

(Below 614Hz)

English Units:

2.0 in/s zero-to-peak

Metric Units:

50.8 mm/s zero-to-peak

Note: Full scale is limited by maximum input above
614 Hz. The maximum input is 2 volts peak, or 20 g
peak. 20 g at 614 Hz is equivalent to 2 inch per
second (the full scale range of the monitor). For
frequencies above 614 Hz, Full scale is equal to
(1228/frequency).

Frequency
Response:

High pass
corner
frequency

AC Voltage:

DC Voltage:

Current Draw:

Frequency:

Inrush:

+24 Vdc Power
Version

Voltage:

Current Draw:

85 to 264 Vac

110 to 370 Vdc

60 mA. typ.

120 mA max.

47 Hz to 440 Hz, or DC.

20A typ. @ Vin=100Vac

40A typ. @ Vin=200Vac

18 to 36 Vdc

300 mA max.

-3 dB corner @ 8 Hz
less than 1% error due to high pass corner above
30 Hz

Low pass corner

Greater than 4 kHz
less than 1% error due to low pass corner below
4kHz

Accuracy

Liquid Crystal
Display and
Buffered output.

30 Hz – 4 kHz:

±3% of full scale, Maximum

8 Hz – 30 Hz

-30% , + 3% of full scale

Trendmaster
Output.

30 Hz – 4 kHz:

±5% of full scale, Maximum

Specifications and Ordering Information

Part Number 141485-01

Rev. D (03/07)

Page 2 of 8

8 Hz – 30 Hz

-30% , + 5% of full scale

Outputs

Buffered
Transducer
Output

Output
Sensitivity:

19.7 mV/mm/s (500 mV/in/s)

Output
Impedance:

500 Ω

Full-scale
Range:

50.8 mm/s (2 in/s) zero-to-peak

Trendmaster®
2000 Interface

Full-scale
Range:

50.8 mm/s (2 in/s)

Overrange:

63.5 mm/s (2.5 in/s)

Frequency
Response:

10 Hz to 1 kHz

Galvanic
Isolation:

Optical @ 1000 Vac or 707 Vdc

Relays

Type

Single-pole, double-throw.

Contact Ratings

Switched Power:

180 watts, 1800 VA Maximum

Maximum
Voltage and
Current

300 Vac at 6 A
28 Vdc at 6 A

Dielectric
Strength

(at sea level):

Contact to Contact: 750 Vrms
Contact to Coil: 1500 Vrms

Life Expectancy

Electrical:

180,000 operations at 6 A, 120 Vac

Displays

Liquid Crystal
Display

Size:

50.8 mm wide x 22.8 mm high
(2.0 inches wide x 0.9 inches high)

Full-scale:

50.8 mm/s (1.999 in/s)

Refresh Rate:

0.8 s

LED Indicators

OK:

One constant ON green LED indicates OK condition
of monitor, transducers, and field wiring. Constant
OFF indicates NOT OK condition. OK LED flashing at 2

Specifications and Ordering Information

Part Number 141485-01

Rev. D (03/07)

Page 3 of 8