M.T.H. PA B-Unit User manual

R
ELECTRIC TRAINS
MTH PA POWERED B-UNIT
OPERATING INSTRUCTIONS
Thank you for purchasing the MTH Electric Trains PA B-Unit locomotive.
This ¼” scale reproduction of the famous PA B-Unit locomotive measures
over 16 1/2” in length and weighs over 4.5 pounds. Despite its scale size, the
locomotive is capable of operating on O-31 3-rail track with any compatible
AC transformer (see the chart on page 10 for a complete list of compatible
transformers and wiring instructions) and is completely compatible with past
MTH PA AA and ABA diesel sets.
The locomotive is equipped with several deluxe features that are simple and
fun to operate. Each feature is described among the following pages which
should be read before the engine is operated. For those of you who can’t wait
to get started, the Quick Start Basic Operating Instructions found on Pages 3
and 4 should be read so that you understand the basics of the operating system.
Notice: This PA B Unit should only be run with engines equipped with
original Proto-Sound from QSI. It will not work with engines equipped
with Proto-Sound 2.0

2
Premier PA B-Unit Operating Manual
Table Of Contents
QUICK START - BASIC OPERATION 3
DCRU® Reverse Unit Operation 3
USING YOUR POWERED PA B UNIT WITH PFA/FYS
EQUIPPED PA AA OR ABA 4
OIL & LUBRICATION INSTRUCTIONS 5
TRACTION TIRE REPLACEMENT INSTRUCTIONS 6
O-31 OPERATION 7
SMOKEUNITOPERATION 8
TRANSFORMER WIRING CHART 10
SERVICE AND WARRANTY INFORMATION 11
HOW TO GET SERVICE 11
LIMITED ONE YEAR WARRANTY 11

3
Premier PA B-Unit Operating Manual
Quick Start - Basic Operation
The MTH PA B Unit contains state-of-the art electronics with several
built-in automatic features for incredibly realistic operation. The PA B-Unit
is easy to operate with your existing MTH PA AA or ABA units using any
compatible standard AC transformer (see the compatibility chart on page 8).
The PA powered B-Unit is controlled by a DCRU® electronic reverse unit
which unit operates in the same manner that all reverse units function by
using forward, neutral and reverse states that are entered each time the throttle
is turned on and off or by using the transformer direction switch (if so
equipped). Simply plug the B-Unit wire harness into the existing sockets of
the PA AA or ABA set to allow Proto-Coupler® equipped engines and
directional lighting systems to function. Once connected, advance the
transformer throttle to cycle all AA and B units together from RESET to
Forward as explained in the DCRU section below.
Prime the operating smoke unit with smoke fluid before operating. Add
15-20 drops of smoke fluid through the smokestack (see Fig. 5on pg. 8), then
gently blow into the stack to eliminate any air bubbles in the fluid.
If you choose not to prime the unit with fluid, turn the smoke unit switch
located under the engine to the OFF position (see Fig. 6 on pg. 8). Running
the engine without a primed smoke unit may cause damage. See the
“ProtoSmoke Unit Operation” section of this book for more information on
smoke unit maintenance.
DCRU® Reverse Unit
As mentioned in the Basic Operating section, the engine is controlled by a
DCRU® reverse unit that contains the standard forward-neutral-reverse states
found on most reverse units. However, when power is first applied to the
track, the reverse unit begins in RESET or what seems like a neutral state.
Power must be interrupted again to
get the locomotive to enter the
forward state. The system will
enter RESET whenever power to
the track is off for three or more
seconds. NEUTRAL should be
referred to as the state between
Forward and Reverse.
RESET
Neutral
Reverse
Neutral
Forward
Figure 1: DCRU™ Cycle Phases

Using The Powered PA B-Unit With PFA/FYS
Equipped MTH PA AA OR ABA
You can utilize the PFA/FYS that came equip on previous MTH Premier
PA AA or ABA by reading the following instructions. Refer to your
Premier PA AA or ABA for operation instruction of PFA/FYS. Your MTH
Premier Powered PA B-unit has a DCRU installed in it, which is not
directly connected to the ProtoSound of your powered A unit. Because the
Powered B-unit is not directly connected to the ProtoSound, the Powered
B-unit will cycle its directional states while the ProtoSound A unit is
playing the PFA/FYS events. To operate the Powered PA B-unit with your
ProtoSound A unit, the only thing to remember is not to set the voltage on
the transformer too high, not above 8-10 volts. If the voltage is set to high,
the Powered B-unit will begin vibrating on the track, as its motors will be
turning. Since the directional cycles of the DCRU are insink with the
number of events played during the PFA/FYS, the Powered B-unit will start
in the same direction as the ProtoSound A unit after the PFA/FYS has
finished playing.
4
Premier PA B-Unit Operating Manual
Because the ProtoSound® system or DCRU® reverse unit found in your
powered MTH PA A unit is not directly connected to the DCRU® unit in
your powered PA B-Unit, you must cycle the power on and off slowly to
maintain proper synchronization between each powered unit’s reverse unit.
If the units should become unsynchronized, simply shut down power for
three or more seconds. Upon repowering, each unit should come up in
RESET. If you choose to operate your existing PA A units in a
“locked-out” state, a lockout switch on the powered PA B-Unit has been
provided so that you can manually “lock-out” the B-Unit in the same
direction the powered A Units are configured.

5
Premier PA B-Unit Operating Manual
Oil & Lubrication Instructions
In order for the engine to perform correctly and quietly, it is important that
the chassis be lubricated before operation. Lubrication should include all
truck block bushings and pickup rollers to prevent them from squeaking.
Use light household oil and follow the lubrication points marked “L" in Fig.
2 below.
The locomotive’s internal gearing in both power trucks has been greased at
the factory and shouldn’t need additional grease until after 50 hours of
operation or one year whichever comes first. Grease cannot be added to the
internal gearing until the body is removed from the chassis which is held in
place by six Phillips screws. The screws are located on each end of the
chassis as seen in Fig. 4 on the following page. After removing the screws,
lift the body away from the chassis and lay the body next to the chassis.
Next, remove the truck blocks from the chassis by unscrewing the large
Phillips motor mount screw on the bottom of each truck block (See Fig. 4).
Once the motor mount screw has been removed, pull the motor away from
Lubricate Pick Up Rollers (L)
Figure 2: Lubricating The Chassis
Grease Idler Gear (G) Grease Idler Gear (G)
Figure 3: Greasing The Chassis Trucks

6
Premier PA B-Unit Operating Manual
the truck block and lightly coat the motor worm gear and bronze drive gear
(in the truck block) with grease. Reassemble the truck and motor, being
careful not to pinch the pickup and ground wires between the truck block
and motor mount. Repeat the procedure for the other motor and truck and
then reassemble the chassis to the body. When reassembling the chassis and
body, be very careful that the lighting wire harnesses are not caught
between the body and chassis as this can lead to a short which may damage
the electronic circuit boards beyond repair.
In addition to the truck block internal gearing, it is a good idea to lubricate
the outside truck block “idler" and “drive" gears with grease. Use the
diagram shown in Fig. 3 on pg. 5 as a guide and add grease to the points
marked with a “G".
Periodically, check the locomotive wheels and pickups for dirt buildup as
this can significantly affect the engine’s ability to perform properly. Dirty
track and dirty wheels can cause both poor electrical contact as well as poor
traction, especially on elevated track sections. Finally, dirt and oil build up
can prematurely wear out the neoprene traction tires.
Traction Tire Replacement Instructions
Your locomotive is equipped with two neoprene rubber traction tires on
each power truck. While these tires are extremely durable and long-lasting
there may arise a time where they will need to be replaced. Should this
occur, you will need to remove the trucks and truck sides on the truck block
from the chassis in order to slip the new tire over the grooved drive wheel.
We suggest you follow the disassembly instructions found in the
Lubrication section on the preceding pages to dissemble the chassis and
truck blocks from the body.
BodyMountScrews
Motor Mount Screw
BodyMountScrews
Figure 4: Removing The body From The Cahssis

7
Premier PA B-Unit Operating Manual
Before the new tire can be installed, you must make sure the old tire has
been completely removed from the groove in the drive wheel. Use a razor
blade or small flatblade screwdriver pry away any remains left from the old
tire that may still be in the drive wheel groove. Once the old tire has been
completely removed, slip the new tire onto the wheel. You may find it
useful to use two small flatblade screwdrivers to assist you in stretching the
tire over the wheel. Be careful to avoid twisting the tire when stretching it
over the wheel. If a twist occurs, the tire will have to be removed and
reinstalled or a noticeable wobble in your engine will occur when operating
the locomotive. In addition, it is important to make sure that the tire is
fully seated inside the groove. Any portion of the tire extending out of the
groove can cause the engine to wobble. A razor blade can be used to trim
away any excess tire that doesn’t seat itself inside the groove properly.
Once the new tire(s) are in place, reassemble the truck sides to the truck
blocks and then reassemble the chassis to the body. Replacement tires are
available directly from MTH Electric Trains.
O-31 Operation
While the MTH PA B-Unit is more than capable of operating on O-31
curves and switches, you may find that certain light freight cars are prone to
derailing when being pulled or pushed by the MTH PA through O-31
switches. Should this occur, we suggest adding weight to the cars making
them heavier and less likely to derail.

8
Premier PA B-Unit Operating Manual
ProtoSmoke®Unit Operation
This Premier diesel locomotive contains a self-powered smoke unit that
outputs smoke through the smokestack on the roof of the engine. The smoke
unit is essentially a small heating element and wick that soaks up and then
heats a mineral oil-based fluid that emits a harmless smoke. The smoke is then
forced out of the stack by a small electric fan. Smoke volume is controlled by
the Proto-Sound 2.0 system.
With a few easy maintenance steps, you should
enjoy trouble-free smoke unit operation for
years.
When preparing to run this engine, add 15-20
drops of smoke fluid through the smokestack
(see Fig. 5). We recommend M.T.H.
ProtoSmoke, Seuthe, LGB, or LVTS fluids. Do
not overfill the unit or the fluid may leak out and
coat the interior engine components.
If you choose not to add the fluid (or have
already added the fluid but choose to run
smoke-free), turn off the smoke unit switch
located under the engine (see Fig. 6). Failure
either to add fluid to the unit or to turn it off
may damage the smoke unit heating element
and/or wicking material.
When the smoke output while running the
engine begins to diminish, add another 10-15
drops of smoke fluid or turn the smoke unit off.
When storing the unit for long periods of time,
you may want to add about 15 drops of fluid to
prevent the wick from drying out.
After removing the engine from storage, add
another 25 drops of fluid, letting the wick soak up
the fluid for 15 minutes prior to operation.
Add Smoke
Fluid Here
Figure 5. Add Smoke Fluid
SmokeUnit
ON/OFF Switch
Figure 6. Smoke Switch
SmokeInspection
Screws
Figure 7. Smoke Unit Inspection
Cover

9
Premier PA B-Unit Operating Manual
If you experience poor or no smoke output when the smoke unit is on and has
fluid, check the wick to see if it has become hard, blackened, and unabsorbent
around the heating element. Remove the smoke unit inspection cover from
the smoke unit’s body (see Fig. 7 on pg. 8). After removing the chassis and
inspection cover screws, lift the inspection plate away and inspect the wick.
If it is darkly discolored and hard, it should be replaced.
Replacement parts and wick replacement instructions are available directly
from the M.T.H. Parts Department (phone: [phone]; e-mail:
[email protected]; mail: 7020 Columbia Gateway Drive, Columbia
MD 21046-1532).

10
Premier PA B-Unit Operating Manual
Transformer Wiring Chart