connected to the same power source, and reduces power loss in the customer’s switch gear and
source transformer.
In addition, the power factor of the system with this harmonic filter corrects the OSCD’s input
power factor to nearly unity over the full load range of the product. Some passive filters may over
correct the power factor at lighter loads. Overcorrecting the power factor can cause voltage ringing
that can affect other equipment.
Harmonic filter general information
The Harmonic Filter is no longer an option for this style of OSCD. The function of the Harmonic
Filter is now integrated into the input of the OSCD. The input rectifier has fast switching transistors
instead of SCR’s and diodes. The OSCD can now control the input current waveform to a near sine
wave shape by controlling how the rectifiers are turned on and off. The Harmonic Filter of the past
injected harmonic current into the input of the OSCD to correct the current waveform.
Since the Harmonic Filter is basically the input to the OSCD there is no need for the additional, pre-
charge, power unit, Harmonic Filter logic board, and contactors for the Harmonic filter of yesterday.
The Harmonic Filter does not require its own pre-charge time, which allows the chiller to start or
restart sooner. This is an important benefit to many customers. The reductions in parts counts will
improve the reliability of the OSCD, and ease of repair. See Figure 47 and Figure 48.
A line inductor is still needed to limit the rate of change in the input current. Without the line
inductor, the input current cannot be properly controlled and harmonic currents would be
generated.
115
YVAM Control Center
Содержание YORK YVAM 0350
Страница 2: ...2 YVAM Control Center...
Страница 10: ...Figure 4 Variable speed drive nomenclature YVAM Control Center 10...
Страница 15: ...Figure 8 System piping and instrumentation diagram P ID 15 YVAM Control Center...
Страница 118: ...Figure 47 Drive logic board Callout Component Callout Component A U35 B U38 C U37 D U36 YVAM Control Center 118...
Страница 154: ...Figure 62 Sample printout status or history YVAM Control Center 154...
Страница 155: ...Figure 63 Sample printout status or history continued 155 YVAM Control Center...
Страница 156: ...Figure 64 Sample printout setpoints YVAM Control Center 156...
Страница 157: ...Figure 65 Sample printout setpoints continued 157 YVAM Control Center...
Страница 158: ...Figure 66 Sample printout schedule YVAM Control Center 158...
Страница 159: ...Figure 67 Sample printout sales order 159 YVAM Control Center...
Страница 160: ...Figure 68 Sample printout security log report YVAM Control Center 160...