Nederman RBU 1300, User Manual

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RBU
b) For models intended for use with a vari-
able frequency drive, switch two of the mo-
tor supply conductors and skip step 4.
4 Switch two of the incoming phase conduct-
ors.
6.2.2 Checking the Y/D time setting
NOTE!
The Y/D time setting is factory preset and does
not normally need to be adjusted.
Switching to D mode before the motor has reached
full speed can damage the start- and control unit. This
is particularly important when an automatic start and
stop is installed. Too long in Y mode results in an un-
necessary delay before the unit delivers full vacuum.
At initial start-up check the Y/D time setting by doing
the following:
• Make sure the motor sound is constant and high
pitched, indicating full motor power, before the mo-
tor switches to D mode.
6.2.3 Checking the start-up and vacuum lim-
iting valve
Perform the check of the start-up and vacuum limiting
valve as described in
Section 7.10 Start-up and vacu-
um limiting valve .
6.2.4 Checking the vacuum level
At initial start-up ensure the vacuum level is at the
correct level by doing the following:
• Check that the vacuum level on the vacuum meter,
Figure 3 item 15, corresponds the specified levels in
Section 3.6 Technical data . See Section 7.11 Vacuum
level for more information about checking the vacu-
um level.
6.2.5 Checking the pilot signal cable func-
tion
For units with pilot signal cable also ensure the fol-
lowing at initial start-up:
• The unit only starts directly when one of the follow-
ing occurs:
• A valve is opened at a worksite, causing the mi-
croswitch to close.
• The test start button is pressed on the start- and
control unit (if available).
• After a delay, the unit goes into idling mode. The
unit remains in idling mode for a specified time be-
fore stopping.
6.3 Parameters for use with a variable
frequency drive
Models intended for use with variable frequency
drives need to maintain a minimum frequency of 20
Hz in order to ensure sufficient lubrication of the
pump. Running the unit at frequencies lower than this
risks damaging the pump. The highest frequency the
unit is intended for use with is 60 Hz. At frequencies
above this, the motor is at risk of overloading.
The U/f ratio curve used by the variable frequency
drive shall be a linear function Stopping of the motor
shall be performed with an unpowered coast to stop.
It is strongly recommended that in the case where
there are no active users the start-up valve is opened
and for models intended for use with a variable fre-
quency drive the frequency is set to the lowest allow-
able. This ensures minimal power consumption for
periods where a strong vacuum is not required.
7 Maintenance
Read Chapter 2 Safety before carrying out mainten-
ance.
It is recommended to install an hour service meter in
the start- and control unit.
NOTE!
The intervals in this chapter are based on the
unit being professionally maintained.
Inspections in the unit are recommended to be made
with only the enclosure roof removed.
WARNING! Risk of personal injury
• Use hearing protection. The sound level is
very high when the unit is run with the en-
closure roof removed.
• Work with electric equipment must be carried
out by a qualified electrician.
• Use proper protective equipment when risk-
ing exposure to the dust.
• Always disconnect the supply voltage before
any servicing, whether mechanical or elec-
trical. Always lock any maintenance switch in
the off position.
• Ensure that the vacuum meter, see Figure 3
item 15, shows that no vacuum is present in
the system during service.
• Make sure the unit is cool before undertaking
an inspection to avoid burn. The unit and its
parts can get very hot.
7.1 General inspection
Perform the following general inspection every 500
hours of operation:
• Inspect the incoming connections. Ensure that all
cables and hoses are tightly fitted.
• Check for signs of corrosion or other damage.
• Check that the ventilation inlet and outlet of the
unit are clear.
• Check that the ventilation to the room is clear (if
placed indoors).
EN
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