TDI TURBOTWIN™
FROM TECH DEVELOPMENT
Publication: T1-795
Issued: August 1, 2008 Page 7
CAUTION
There is often weld slag, grindings, thread shavings,
hardened compounds and other heavy debris in new
packagepiping & at new site installations. Therefore,
at commissioning (before running motors), TDI
recommendsa “blow-down”proceduretopurgemotor
supply lines of all hard debris that may otherwise
damage the motor severely. While T100
TURBOTWIN motors are highly tolerant of
contamination in the air/gas supply, motor life can be
greatlyincreased by usinga coarse meshstrainer. At
sites where dirty supply air/gas is present, use &
maintenance of a #40 mesh Y-strainer, upstream of
the motors, is highly recommended.
NOTE
Expensive moisture abatement (air/gas drying) is not
required, as this has no effect on the motors.
2.3 MOTOR CONTROLS
A preferred motor supply control valve is typically a
pilot-operated type, which can be pneumatically or
electrically actuated. The valve should be located
relatively close to the motor inlet, to prevent motor
over-running at the end of the cycle (especially on
starter applications).
CAUTION
Proper supply pressure “matching” and over-speed
control is highly recommended on all installations of
Models T100MS (See section 2.5)
Do not use supply pressure indications only as a
method to properly set the motors’ supply pressure. A
pressure regulator is required, where dynamic air/gas
motor supply pressure is great enough to exceed the
motor operating pressure (at the inlet port) and/or
where a “default” supply pressure would produce
motor output speeds beyond what is specified for
the application.(Result is over-speed, not
necessarily an indicated over-pressure). Both
over-pressure & over-speed will reduce life of the
motor & wastes supply air/gas (increases
operating costs).
2.4 INLET PRESSURE CHECK PORT
(checking dynamic operating pressures)
A 1/4" NPT port is located on the motor housing, under
the air inlet. This port can be used to check the supply
pressure at the motor when the motor is operating. To
check dynamic pressure, remove the 1/4" NPT pipe
plug and save for later use. Install a pressure gauge to
read at this port. Using Loctite Pipe Thread Sealant or
equivalent, replace ¼” NPTpipe plug whendone. This
pressure monitoring line/gauge may also be
permanently installed. Alternately, a pressure
transducer may be installed at the pressure check port
and electrical lines routed to a digital display at the
operator's station.
2.5 MATCHING MOTOR OUTPUT (SPEED)
TO LOAD
A hand held tachometer should be used to double-
check motor output speeds. Motor supply pressure
should be set at the minimum pressure required to
insure the motor runs the speed/load required by the
application.
It is recommended that all starters be installed with a
discrete supply pressure regulator. Do not use supply
pressure only, (such as the default fuel gas pressure
onthe package) as indicators ofmotor speed &output,
which typically do not account for:
Varyingfuel gas pressures (on variousturbine
engine models)
Varying compressor loads during start-up
Varying site conditions (temperatures, etc…)
Varying turbine engine ramp-up speeds (&
time) required.
NOTE
Starter motor over pressure (even where starter
supply pressure minimally exceeds that needed for
proper ramp-up speeds/times) may result in engine
turning too fast, too quickly… a.k.a. “flame-out.” In
these cases simply reducing starter supply
pressure will generally correct this.
3.0 MOTOR OPERATION
WARNING
Do not operate the TDI TURBOTWIN starter at
dynamic supply pressures greaterthan the pressure
rating on the nameplate. This dynamic pressure is
measured at the motor inlet while the motor is
running.
Static (non-flowing) supply pressure will
always be higher than theoperating (dynamic)
pressure.
