True Blue Power
®
9
Manual Number 9017680
a division of Mid-Continent Instrument Co., Inc.
Revision G, July 17, 2019
3.3.3 Pin Description Information
Inverter Power Input:
28VDC Input (Positive) –
No24 to 32 VDC from the aircraft 28 VDC power bus
through a circuit breaker.
28VDC Return
(
Negative) –
Internally this pin is isolated from the inverter case/chassis.
Typically this lead is connected to aircraft ground. In aircraft with a negative return bus
connect this lead to the return bus.
Common practices for the connecting the -28V of power devices in aircraft vary.
The TI1200
Series passes DO-160G Section 21 conducted emissions testing using both methods (below)
as listed in Section 5.2 of this report.
1. The negative lead connects from the device to the negative power bus.
2. The negative lead connects from the device to the negative power bus, and a second
lead connects to the aircraft structure close to the power device.
Inverter AC Output:
The AC output pins of the TI1200 series inverter are isolated from the inverter case/chassis.
AC Volt Output
– 115VAC, 60Hz, 400Hz or 230VAC, 50Hz. The AC output can be
considered as “Line” or “Hot” when referenced to terrestrial/utility power designations.
AC Volt Return
– The AC return can be considered as “Neutral” when referenced to
terrestrial/utility power designations.
On/Off ENABLE Control:
For most TI1200 models (6431200-1 through -6) the inverter output is ENABLED by
connecting the ENABLE pin to either DC Negative or to aircraft ground. If the inverter is to be
ENABLED at all times then the ENABLE pin can be connected directly to DC Negative. By
utilizing a switch between this pin and ground or negative, the switch will allow remote on/off
control of the unit.
For only the TI1204 6431200-7 model, the inverter is ENABLED if this connection is open or
connected to ground. To turn the inverter OFF remotely, a switch must be used to pull-up this
pin to 28 VDC positive.
On all models the ENABLE pin has approximately 11 VDC present from an internal source
and is limited to less than 1 mA. A small low-current relay or open-collector transistor can be
used to control ENABLE from other systems.
3.3.4 Wire Selection
Use of PTFE, ETFE, TFE, Teflon, or Tefzel stranded insulated wire is recommended for
aircraft use. Use the wire gauges for each of the pins in the connector per table 3.3.2:
Note
– Because of lower current requirements, the TI1202 600VA 6431200-5 model can be
installed using 10 AWG for 28VDC input power and 16 AWG for the AC output.
3.3.5 Circuit Breaker on Input Power:
Connect TI1200 1200VA models to the aircraft 28 VDC bus using a 60-70 Amp circuit breaker.
(For the 600VA 6431200-5 use a 30 or 35 Amp circuit breaker.
3.3.6 Circuit Breakers on AC Output:
Use of a circuit breaker on the AC output is optional. On 115VAC models a 10 Amp
circuit breaker is sufficient for the full inverter 1200VA output. For 230VAC /1200VA
models use a 5 Amp circuit breaker. For, 230VAC/ 600VA models use a 2.5 Amp circuit
breaker. For convenience at each AC outlet, individual circuit breakers of 1 to 5 amps
each can be used. If a single pole breaker is used, install the breaker on the AC Output. If
