AOC 15 user manual Electrical Installation

7.0 Electrical Installation 54

The following sections discuss the wind turbine wiring and utility connection requirements and procedures. Wire connections to the three-phase control box, dynamic brake boxes and twist cable junction box are site specific, but should follow the general guidelines and wiring drawings available from AOC.

7.1Electrical Interface to Utility

The utility interface is site specific and must be coordinated with the local utility or other responsible party. A kWh meter for each machine is recommended.

The wind turbine may be interfaced with a preexisting low voltage 480V 60Hz (400V 50Hz) supply or it may require its own step up transformer to the system distribution voltage.

∙Interface at the 400/480 VAC level:

For single wind turbine installations the wind turbine can be interfaced directly with the 480/400 VAC utility system, if sufficient transformer capacity exists (75 kVA per turbine). This also applies to commercial and industrial installations with an adequately sized 480/400 VAC panel and distribution system. The wind turbine should be on a dedicated circuit breaker/fuse of proper capacity rating.

∙Interface at voltage levels greater than 480/400 VAC:

For single or multiple wind turbine installations it may be necessary and/or desirable to install a step up transformer between the 480/400 VAC wind turbine and the higher voltage utility system. For example, in a single unit installation interfacing with a 13.8 kV utility system, a minimum 75 kVA transformer with a 13.8 kV/480V ratio would be necessary. Since wind turbine output is variable, care must be taken to properly size the step-up transformer. The winding configuration may also affect system performance. The AOC 15/50 generator is WYE connected. The interfacing transformer is typically connected with WYE primary and DELTA secondary.

Figure 7-1 illustrates the simplest form of a utility interface. Utility interconnection should be specifically engineered for each site. This manual only suggests installation procedures from the control box to the wind turbine. Applicable national and local codes must be followed. Careful research and consultation during the planning stage can avoid expensive and dangerous mistakes. A licensed electrician may be required to install all interconnection wiring. See Appendix M for details on wire sizing.

NOTICE: Use of the material contained in this document is subject to the warning on page Iv and the disclaimer on page v of this document.

DOC012R02 AOC 15/50 User Manual Nov 2001