BTT-40P
Current Transformer
Description
BTT-40P current transformer block
BTT-40P is an aviation current-transformer block used in the protection and regulation circuits of 40 kVA three-phase AC generators. Its purpose is not to supply aircraft consumers directly. The block measures phase-current relationships and provides signals used by the generator control and protection equipment during both independent and parallel operation.
The complete marking must be checked when selecting a replacement. BTT-40P belongs to the same functional family as other BTT units, but a similar housing or rating does not establish interchangeability.
Full descriptionCollapse description
BTT-40P function in the generator channel
The documented construction combines four toroidal current transformers, a U1 assembly with three U-shaped transformers and a U2 assembly with three diodes. Three toroidal transformers provide signals for reactive-load sharing, while the fourth participates in active-load sharing and current-unbalance protection. The U-shaped transformers operate with the current transformers installed at the generator side to protect the generator and its feeder.
For maintenance, the unit also has test windings. Connections, phase orientation and the direction of the conductors through the block are therefore part of the installation data and must not be inferred from appearance alone.
BTT-40P electrical and environmental data
The published nominal primary current is 111 A at a 208 V generator-channel voltage and 400 Hz frequency. A maximum current of 138.5 A is permitted for a limited portion of service life. The documented mass is not more than 2 kg. Published environmental limits include operation from −60 to +60 °C, cyclic exposure up to +80 °C, vibration from 5 to 300 Hz and linear acceleration up to 10 g.
These are identification and selection data. Acceptance testing, insulation checks and adjustment must follow the passport and the approved manual for the exact execution.
BTT-40P aircraft and system application
BTT-40P is documented in the electrical-equipment manuals for the Mil Mi-24 family. The generator and protection configuration must still be checked against the aircraft modification and wiring documentation. One associated protection product listed in this system class is the BZU-376SP-4S; its presence in a specific installation does not make the two products interchangeable.
Ordering and identification of BTT-40P
An enquiry should state BTT-40P exactly, the required quantity, condition and documentation. Please provide a readable data-plate photograph and, when possible, the designation of the generator and protection unit. Related current-transformer blocks are available in Power Transducers. Actual availability, delivery scope and test documentation are confirmed separately.
Technical details
- Product Type
- Aviation current transformer block
- Part Number
- BTT-40P
- Alternative Designations
- BTT-40P; BTT40P; BTT 40P; БТТ-40П
- Primary Function
- Generator current measurement for protection and load-sharing circuits
- Generator Power Class
- 40 kVA
All specificationsCollapse specifications
- Nominal Primary Current
- 111 A
- Maximum Primary Current
- 138.5 A for a limited portion of service life
- Generator-Channel Voltage
- 208 V AC
- Operating Frequency
- 400 Hz
- Construction
- Four toroidal current transformers; U1 assembly with three U-shaped transformers; U2 assembly with three diodes
- Protection Functions
- Generator and feeder differential/current-unbalance protection
- Parallel-Operation Functions
- Active- and reactive-load sharing signal circuits
- Operating Temperature
- −60 to +60 °C
- Cyclic Temperature Exposure
- −60 to +80 °C
- Vibration Range
- 5–300 Hz, acceleration up to 5 g
- Linear Acceleration
- Up to 10 g
- Mass
- Not more than 2 kg
- Documented Aircraft Context
- Mil Mi-24 family; confirm the exact aircraft modification
- Associated Equipment
- 40 kVA AC generator channel and compatible generator protection/regulation unit
- Compatibility
- Confirm by complete marking, phase arrangement, conductor direction, connector layout and aircraft wiring documentation
- Documentation
- Product passport and approved aircraft electrical-equipment manual
Payment & delivery
Orders ship from our hub in Dubai. Partner stock is first transferred to Dubai, then shipped to you.
Dubai stock: 100% before dispatch. Partner stock (Remote stock) and Pre-order: 50% advance payment to start the order and 50% before shipment from Dubai to you.
Availability, lead time, delivery cost and payment terms are confirmed for your order before payment.
Payment & delivery terms