NOVAR 300 uses true rms measuring techniques together with appropriate mathematical calculations in preference to mean sensing and zero crossing detection which has proved inaccurate on systems with distorted waveforms. The NOVAR 300 should be connected to the system as shown in the appropriate diagrams (Figures 1 and 2).
Page 4
NOVAR 300 Operation & Maintenance Manual NOVAR_CM Page 4 of 29 For contact pairs fitted see number of stages To Load Alarm (if fitted) FIGURE 1 - Wiring diagram for volt free contacts...
Page 5
NOVAR 300 Operation & Maintenance Manual NOVAR_CM Page 5 of 29 Common For contact pairs fitted see number of stages To Load Alarm (if fitted) FIGURE 2 - Wiring diagram for common contacts...
NOVAR 300 Operation & Maintenance Manual NOVAR_CM Page 6 of 29 1.2 DESCRIPTION AND OPERATION Multi-stage controllers are available in standard units of 6 and 12 stages. These provide up to 12 pairs of "volt-free" contacts. The following switches are mounted on the controller front panel :...
NOVAR 300 Operation & Maintenance Manual NOVAR_CM Page 7 of 29 2. TECHNICAL SPECIFICATION 2.1 RATINGS, OPERATING RANGES & FEATURES Voltage Rating (Vn) 110 V, 120 V, 415 V, 480 V. Others available in range 63.5 V to 500 V max.
Page 8
The time required to safely discharge a capacitor can be Safety lockout set to any of 8 different values. The NOVAR will not allow any capacitor to be re-energised until this time has elapsed. Providing that the safety lockout time has passed, the capacitor can be called after one fifth of the programmed time.
Page 9
Models without the automatic exit from manual are available. Signals failure to meet target cos ϕ Alarm output See also Self Test At reset and every ten minutes in operation, the NOVAR Self Test executes internal hardware check correct functioning.
Before connection of the NOVAR into a customer's system, ensure that the safety lockout time programmed into the NOVAR is equal to or greater than that required for safe discharge of system capacitors. Unless this has been specified on ordering, the NOVAR will be set to 60 seconds.
NOVAR 300 Operation & Maintenance Manual NOVAR_CM Page 13 of 29 3.2 USER ADJUSTMENTS The following user adjustments are available and should be set during commissioning. Refer to also to Figure 4. Parameter Fascia Key Means of Selection Sequence DIL switch *...
Page 14
F - Dual mode button: capacitor switching (man) and display selection (auto) G - DIL switch (sequence, time and limit setting) H - Power on indication LED J - Switching in progress, circuit is capacitive K - Switching in progress, circuit is inductive FIGURE 4 - NOVAR indication and user adjustments...
Settings of sequence, lockout time and stage limit should be set prior to powering up the NOVAR. When a controller leaves the factory, the DIL switch will be pre-set to the following default values, regardless of model type, unless specified on the order. Refer to Figure 5.
(an ‘L’ will appear in the fourth display digit). Note: The limit is the number of capacitors connected to the NOVAR and must be set correctly. If the limit is set higher than the number of capacitors connected then the system response will be slowed down.
(i.e. NOVAR 300 will switch capacitors in circuit when the input lagging vars exceed three quarters of a capacitor step size . NOVAR 300 will switch capacitors out of circuit when the input leading vars exceed three quarters of a capacitor step size .) The value of C/K can be directly entered into the unit.
As above, this value can be directly entered into the unit. NB: The NOVAR 300 calculation has been formulated in such a way that it will work for any value of secondary amps and volts which can be used with the unit. However, if the nominal secondary amps used is other than 5 amps, the value represented by the scalings on the c/k potentiometer will no longer be the actual capacitor starting current in amps.
For three of the others, NOVAR 300 will give indication of a connection error as follows. At system unity power factor, the NOVAR 300 error mode is looking for a phase angle of 90° between amps and volts. As a system can in theory be operating anywhere within a band of 90°...
Page 21
NOVAR 300 Operation & Maintenance Manual NOVAR_CM Page 21 of 29 FIGURE 7 - System vector diagrams...
4. FAULT FINDING AND TEST PROCEDURES 4.1 FAULT FINDING When power is first applied to a NOVAR it examines both its own circuitry and the system into which it has been connected. If it finds any faults in either situation, it will signify this as follows.
IND LED briefly. NB This is not an indication of a software error in the NOVAR - it is impossible for a NOVAR to be despatched unless its software is correct. If either of these situations does occur, there will be some cause not caught by the above specific error traps (e.g.
NOVAR 300 Operation & Maintenance Manual NOVAR_CM Page 24 of 29 4.2 TEST PROCEDURES 4.2.1 Test equipment This equipment should be capable of supplying a single phase voltage and a current which is in phase with this voltage, both of which should be adjustable. The supply should be of adequate rating to meet the voltage input and to supply up to a minimum of 50% of the full scale current rating of the controller.
Page 25
NOVAR 300 Operation & Maintenance Manual NOVAR_CM Page 25 of 29 4.2.2.9 Allow the controller to count up to its top limit. 4.2.2.10 Check that all of the output relays are now switched on. 4.2.2.11 Reduce the current to zero: both the IND LED and the CAP LED should now be extinguished.
If a fault in the controller is suspected, it is recommended that the complete unit is replaced. Because of the complexity of a device such as a NOVAR and the fact that it does contain calibration variables particular to its hardware on leaving the factory, any hardware changes subsequent to this will almost certainly lead to a loss in performance.
5.3.3 Remove the standard cover from the front of the NOVAR and place the lockable cover over the front of the NOVAR, with the hinge placed towards the left of the NOVAR. Press together firmly. 5.3.4 Open the lockable cover door and wipe away any excess adhesive with a clean dry cloth.
NOVAR 300 Operation & Maintenance Manual NOVAR_CM Page 28 of 29 6. CIRCUIT DESCRIPTION Figure 6 shows a block diagram of the Controller. This comprises two printed circuit boards with plugs and sockets providing all the board interconnections. There are two versions of the 'Relay' PCB circuit.
Page 29
Voltage Power Supply Input To 5V Logic Relay Reset Circuits Relays Drivers Dropper T2 CT Scaling Current Scaling Display Input Display MICRO-CONTROLLER Driver C/k and cos ϕ pots LEDs Driver Switch Switches Select FIGURE 8 - NOVAR 300 Block diagram...
Need help?
Do you have a question about the NOVAR 300 and is the answer not in the manual?
Questions and answers