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Entek IRD 6652 DSP Protection Monitor
Configuration
Understanding Speed Bands
Speed bands give you the ability to set different alarm levels based on the speed of the
machine. The 6652 DSP allows you to set up to seven bands based on machine speed. You
use the options on the SPD BND submenu (page 24) to define both the speed bands and the
alarm actions in each of the speed bands.
Note:
In order to use speed bands, the 6652 DSP monitor requires a 1x tachometer input signal.
For each speed band, you can define an alarm setpoint multiplier when the machine speed is
within the band. The 6652 DSP multiplies the basic amplitude alarm setpoint for the
channel by the multiplier for the speed band. You use the options on the MULT1 and MULT
2 submenus to choose the alarm multiplier for each band (page 29). You set the Alert and
Danger alarm setpoints on the ALARMS submenu (page 18).
For each speed band, you can also define the alarm action when the machine speed is within
the band. The 6652 DSP can:
l
Multiply the channel alarm setpoint by the multiplier for the speed band.
l
Inhibit the Danger alarm relay.
l
Both multiply the channel alarm setpoint and inhibit the Danger alarm relay.
l
Neither multiply the alarm setpoint nor inhibit the Danger alarm relay. In this case, the
6652 DSP uses the alarm setpoint for the channel.
The following table provides more details on alarm action:
The 6652 DSP monitor allows you to set two limits for the upper edge of a band. One limit
(LO) defines the upper edge of the band when the machine speed is falling. The other limit
(HI) defines the upper edge of the band when the machine speed is rising. This can prevent
alarm relay “chattering” when the machine speed varies slightly at the edge of a band.
Consider the following example:
Then the monitor defines the bands as follows:
Note:
Band 1 always starts at 0 RPM.
BND ACT
→
NONE
BOTH
MULTI
INHIB
Alert message
Unaffected
Multiplied
Multiplied
Unaffected
relay
Unaffected
Multiplied
Multiplied
Unaffected
Danger message
Unaffected
Multiplied
Multiplied
Unaffected
relay
Unaffected
Inhibited
Multiplied
Inhibited
RPM1 LO
1000
RPM2 LO
3000
RPM3 LO
5000
RPM1 HI
1200
RPM2 HI
3200
RPM3 HI
5200
Speed rising
Speed falling
Band 1
0–1200 RPM
0–1000 RPM
Band 2
1200–3200 RPM
1000–3000 RPM
Band 3
3200–5200 RPM
3000–5000 RPM
Band 4
5200 and higher RPM
5000 and higher RPM
