Curtis 1204 User manual

MANUAL
© 1999 CURTIS INSTRUMENTS, INC.
DESIGN OF CURTIS 1200 SERIES
CONTROLLERS PROTECTED BY U.S.
PATENT NO. 4626750.
MODEL
1204/5
MOTOR CONTROLLERS
CURTIS PMC
235 East Airway Boulevard
Livermore, California 94568 USA
Tel: [phone]
Fax: [phone]
www.curtisinst.com
1204 / 1205 Manual
p/n 98690, Rev. B: May 1999

1204 / 1205 Manual
p/n 98690, Rev. B: May 1999
© 1999 CURTIS INSTRUMENTS, INC.
This electronic version of the 1204/1205 manual is offered as a convenience to our
customers. You may download any or all of it.
Ifyouwouldlikeahardcopyofthepublishedmanual,pleaseorderitbypartnumberfrom
the Curtis office nearest you.
The electronic version of the manual is identical to the printed version published in May
1999.Bookmarkshavebeenaddedtotheelectronicversiontospeedtheprocessofgoing
directly to a particular part of the document.
CURTIS INSTRUMENTS, INC.
200 KISCO AVENUE
MOUNT KISCO, NEW YORK 10549 USA
☎914-666-2971 FAX [phone]
■CURTIS PMC
235 EAST AIRWAY BOULEVARD
LIVERMORE, CALIFORNIA 94550 USA
☎925-961-1088 FAX [phone]
■ ADDITIONAL OFFICES located in
Bulgaria, China, England, France, Germany,
India, Italy, Japan, Netherlands, Puerto Rico,
Russia, Sweden, and Switzerland

Curtis PMC 1204/1205 Manual iii
CONTENTS
1. OVERVIEW .................................................................... 1
2. HARDWARE INSTALLATION .................................... 3
Controller ................................................................. 3
Throttle ..................................................................... 4
Other Hardware ........................................................ 6
Main contactor .................................................. 7
Forward/reverse contactors ................................. 7
Forward/reverse switches .................................... 7
Keyswitch........................................................... 8
Polarity protection diode.................................... 8
Control wiring fuse ............................................ 8
Power wiring fuse............................................... 8
3. WIRING.......................................................................... 9
Connections: Low Current........................................ 9
Connections: High Current ...................................... 9
Wiring: Series Motors ............................................... 10
KSI ................................................................... 10
Forward/reverse (with standard power wiring) ... 11
Plug braking ............................................... 11
Freewheeling ............................................... 11
Forward/reverse (with alternate power wiring) ... 12
Reversing with 4×SPDT contactors ............ 12
Mechanical reversing switch........................ 13
Throttle pot ....................................................... 14
Standard potbox ......................................... 14
Pots for twist-grip throttles ......................... 14
Reduced speed operation ............................ 15
Electronic throttle .............................................. 16
Wiring: Permanent Magnet Motors .......................... 17
Installation Checkout ................................................ 20
4. MAINTENANCE AND ADJUSTMENT ...................... 22
Controller ................................................................. 22
Potbox ....................................................................... 24
CONTENTS
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12345678901

iv Curtis PMC 1204/1205 Manual
5. TROUBLESHOOTING AND BENCH TESTING ...... 25
Operational Notes ..................................................... 25
In-Vehicle Diagnostic Tests ...................................... 28
Bench Testing ........................................................... 32
6. GLOSSARY: FEATURES AND FUNCTIONS ............ 35
APPENDIXES
A. Functional Description of 1204/1205 Controllers............ A-1
B. Pulse Width Modulation .................................................. B-1
C. Specifications .................................................................... C-1
CONTENTS
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Curtis PMC 1204/1205 Manual v
FIGURES
FIG. 1 Curtis PMC 1205 electronic motor controller............... 1
FIG. 2 Mounting dimensions,
Curtis PMC 1204/1205 controller ................................ 3
FIG. 3 Mounting dimensions,
Curtis PMC potboxes PB-5, -6, -9, and -10 .................. 5
FIG. 4 Curtis PMC footpedal FP-2 .......................................... 5
FIG. 5 Typical installation,
Curtis PMC 1204/1205 controller ................................ 6
FIG. 6 Basic wiring for use with series motors .......................... 10
FIG. 7 Alternate control wiring, to provide freewheeling .......... 11
FIG. 8 Alternate power wiring, for reversing with
4×SPST contactors ........................................................ 12
FIG. 9 Alternate power wiring, for reversing with
mechanical forward/reverse switch arm .......................... 13
FIG. 10 Standard throttle pot, 0–5kΩ........................................ 14
FIG. 11 Bi-directional twist-grip throttle with
10 kΩcenter-tapped, 4-terminal pot ............................. 14
FIG. 12 Bi-directional twist-grip throttle with
20 kΩpot and controller with optional
5kΩ–0 throttle input ..................................................... 15
FIG. 13 Reduced speed operation (with standard 0–5kΩpot) .... 15
FIG. 14 Curtis PMC electronic throttle (ET series) .................... 16
FIG. 15 Basic wiring for use with
permanent magnet (PM) motors ................................... 17
FIGURES

vi Curtis PMC 1204/1205 Manual
FIG. 16 Alternate PM motor wiring, using
4×SPST contactors to provide freewheeling................... 18
FIG. 17 Preferred PM motor wiring for
freewheeling or dynamic braking ................................... 18
FIG. 18 Adjustment pots ............................................................ 23
FIG. 19 Guide to troubleshooting procedures............................. 27
FIG. 20 Setup for bench testing .................................................. 33
FIG. A-1 Block diagram, Curtis PMC 1204/1205 controller ....... A-1
FIG. B-1 Pulse width modulation ................................................. B-1
FIGURES

1
Curtis PMC 1204/1205 Manual
OVERVIEW
1
Fig. 1 Curtis PMC
1205 electronic motor
controller.
Model 1204 has
identical connections.
OVERVIEW
Curtis PMC Model 1204 and 1205 electronic motor speed controllers
are designed to provide smooth, silent, cost-effective control of motor
speed and torque on a wide variety of industrial electric vehicles.
Like all Curtis PMC 1200 series controllers, the 1204/1205 models offer
superior operator control of the vehicle’s motor drive speed. Key features
of the 1204/1205 controllers include:
✓Infinitely variable drive and brake control
✓Power MOSFET design provides high efficiency (for reduced motor
and battery losses) and silent operation
✓High pedal disable (HPD) function monitors throttle status during
turn-on and prevents operation until throttle has been returned to
neutral [optional feature]
✓Thermal protection and compensation circuit provides both under-
temperature and overtemperature cutback, as well as steady current
limit throughout the entire operating range
✓Undervoltage cutback function protects against low battery voltage,
including low voltage caused by external loads
More Features ☞

2
Curtis PMC 1204/1205 Manual
OVERVIEW
✓Pot fault circuit shuts off controller if pot wires open
✓Simple installation with no adjustments required
✓Tin-plated solid copper bus bars
✓Push-on connectors for control wiring
Familiarity with your Curtis PMC controller will help you to install and
operate it properly. We encourage you to read this manual carefully. If you
have questions, please contact the Curtis office nearest you.
Working on electric vehicles is potentially dangerous. You should
protect yourself against runaways, high current arcs, and outgassing
from lead acid batteries:
RUNAWAYS —Some fault conditions could cause the vehicle to run
out of control. Jack up the vehicle and get the drive wheels off the
ground before attempting these procedures or any other work on the
motor control circuitry.
HIGH CURRENT ARCS —Electric vehicle batteries can supply very high
power, and arcs can occur if they are short circuited. Always open the
battery circuit before working on the motor control circuit. Wear
safety glasses, and use properly insulated tools to prevent shorts.
LEAD ACID BATTERIES —Charging or discharging generates hydrogen
gas, which can build up in and around the batteries. Follow the
battery manufacturer’s safety recommendations. Wear safety glasses.
☞
CAUTION

3
Curtis PMC 1204/1205 Manual
HARDWARE INSTALLATION
2HARDWARE INSTALLATION
CONTROLLER
The controller may be oriented in any position, but the location should
be carefully chosen to keep the controller as clean and dry as possible.
If a clean, dry mounting location cannot be found, a cover must be
used to deflect dirt and water splash.
The controller should be fastened with four screws to a clean, flat
metal surface that provides an adequate heat sink. The mounting surface
is an integral part of the overall heatsinking of the controller, and affects
its ability to dissipate heat. The case outline and mounting hole dimen-
sions are shown in Figure 2. If your controller is an adjustable model, be
sure to mount it so as to allow access to the adjustment screws.
Although not usually necessary, a thermal joint compound can be
used to improve heat conduction from the case to the mounting surface.
Fig. 2 Mounting
dimensions,
Curtis PMC 1204/5
controller.
3.3
(0.13)
70 (2.8)
133 (5.25)
MODEL 1204: 174 (6.85)
MODEL 1205: 225 (8.85)
113 (4.45)
130 (5.13)
146 (5.75)
16.5 (0.65)
1204: 19 (0.75)
1205: 44 (1.75)
7 (0.28) dia.
8 (0.33) dia.
22
× 19 × 3
(0.85
× 0.75 × 0.125)
6 (0.25)
male push-on,
3 plcs
Dimensions in millimeters and (inches)

4
Curtis PMC 1204/1205 Manual
THROTTLE
The standard controller throttle input is 0–5kΩ. Curtis PMC potboxes
(PB-5, -6, -9, -10) are designed to match this input. Some of these
potboxes have a built-in microswitch, eliminating the need to install a
separate pedal-actuated microswitch. Curtis PMC also offers a self-
contained footpedal unit (FP-2) that eliminates the need for fabricating
and installing a pedal-potbox linkage. Any potbox that provides a nominal
0–5kΩoutput (controller output begins at ≈300 ohms, full output is
≈4400 ohms) will work with the standard throttle input. For other types,
contact your Curtis office.
If a Curtis PMC potbox is used, it must be mounted so as to allow
connection between the potbox lever arm and the vehicle accelerator
linkage. The potbox mounting dimensions are shown in Figure 3. The
lever arm provides a series of holes so that the accelerator pedal “throw”
can be converted into the correct amount of potentiometer rotation. Use
of a second return spring on the pedal, in addition to the potbox return
spring, is required to prevent an uncontrollable full-on throttle input
(which could happen if there was a single spring, and it broke). If the self-
contained potbox spring is insufficient to return the pedal by itself, two
additional pedal return springs must be used.
It is also required that the accelerator pedal hit a mechanical stop at
its full-on position just before (≈1 mm [1/32"–1/16"]) the potbox lever
hits its own full-on stop. This mechanical stop will prevent the potbox
lever arm from bending if undue force is put on the pedal. Protection of
the potbox from water and dirt will help avoid problems of corrosion and
electrical leakage.
After the potbox has been mounted, operation of the pot can be
tested by measuring the resistance between the two wires with an ohm-
meter. With the pedal not applied, the resistance should be less than 50
ohms. As the pedal is applied, the resistance should rise smoothly until it
reaches a value between 4500 and 5500 ohms. Values below 4500 ohms
may cause a reduction in efficiency and top speed. Values above 7000
ohms indicate a defective potbox, and will cause controller shutdown.
Curtis PMC’s electronic throttle (ET-XXX), manufactured by Hardellet,
is designed for 24–36V systems, and can be used with any 1204/1205
controller having the 0–5V throttle input option.
HARDWARE INSTALLATION

5
Curtis PMC 1204/1205 Manual
Fig. 3 Mounting
dimensions,
Curtis PMC potboxes
PB-5, -6, -9, and -10.
HARDWARE INSTALLATION
10 (0.38)
32
(1.25)
6
(0.25) 89 (3.5)
60
(2.37)
102 (4.0)
45
°
Dimensions in millimeters and (inches)
RIGHT-HAND OPERATION LEFT-HAND OPERATION
COM. N.O. N.C. N.C. N.O. COM.
WITH MICROSWITCH: PB-6
WITHOUT MICROSWITCH: PB-5 WITH MICROSWITCH: PB-9 WITHOUT MICROSWITCH: PB-10
42 (1.65)
52 (2.06)
Dimensions in millimeters and (inches)
≈ 15 °
244 (9.6)
112 (4.4)
112
(4.4)
1.8 m
(6 ft)
WIRING:
BLACK = throttle input BLUE = switch, common (GREEN is not used with
WHITE = throttle input ORANGE = switch, normally open 1204/1205 controllers)
BLK
ON
GRN
(not used)
WHT
ORG
BLU
COM.N.O.
Fig. 4 Curtis PMC footpedal FP-2.

6
Curtis PMC 1204/1205 Manual
OTHER HARDWARE
The recommended hardware for a typical 1204/1205 controller installa-
tion is shown in Figure 5.
Contactors should be mounted in a clean, dry location. If such a
location is unavailable, a cover should be used to deflect dirt and water
splash.
The precharge resistor connected to the main contactor, and the coil
suppression diodes connected to the main contactor and to the forward/
reverse contactors, are somewhat delicate components. Care should be
taken to prevent damage to them during installation.
CONTROL
WIRING
FUSE
POWER
WIRING
FUSE
POLARITY
PROTECTION
DIODE
KEYSWITCH POTBOX
FORWARD/REVERSE SWITCH
(SPDT, center off)
FR
F/R CHANGEOVER CONTACTOR
(Albright DC182 shown)
MAIN
CONTACTOR
(Albright
SW180
shown)
A1 A2
S1
S2
SERIES
MOTOR
BATTERY
A2M-
B- B+
B-
B+
PRECHARGE RESISTOR, such as Curtis PMC p/n MP-2
COIL SUPPRESSION DIODE, such as Curtis PMC p/n MP-1
(250Ω, 5W)
N.C.
COM.
FWD REV
Fig. 5 Typical installation,
Curtis PMC 1204/1205 controller.
HARDWARE INSTALLATION

7
Curtis PMC 1204/1205 Manual
HARDWARE INSTALLATION
Main Contactor
Most applications use a main contactor in series with the battery positive
(B+) cable to disconnect all power when the system is turned off, as shown
in Figure 5. A heavy-duty single-pole, single-throw (SPST) contactor with
silver-alloy contacts is recommended, such as an Albright SW80 or
SW180 (available from Curtis).
A coil suppression diode, such as a Curtis PMC p/n MP-1 (which is
rated at 100 volts, 3 amps), should be used on the contactor coil.
The rapid charging of the controller’s internal filter capacitors causes
a high inrush current to flow briefly when the contactor closes. To extend
contact life, a precharge resistor, such as Curtis PMC’s p/n MP-2, is
recommended; the resistor precharges the capacitors and reduces the
inrush current through the contacts. If an inexpensive “can”type sole-
noid is used, the resistor is mandatory to prevent contact welding.
Forward/Reverse Contactors
The forward/reverse contactor coils must match the vehicle’s battery
voltage. Use of two single-pole, double-throw (2×SPDT) contactors is
recommended. Although inexpensive “can”type solenoids can be used,
their ratings are typically not sufficient for long life. Changeover contactor
sets —such as the Albright DC88 and DC182 (available from Curtis) —
are therefore recommended.
A coil suppression diode, such as a Curtis PMC p/n MP-1 (which is
rated at 100 volts, 3 amps) should be used on each of the forward/reverse
contactor coils.
Forward/Reverse Switches
The forward/reverse contactor coils can be operated by any type of
single-pole, double-throw (SPDT) center-off switch capable of switching
the coil current. Toggle or rocker switches are generally used.
If your controller has the optional high pedal disable (HPD) feature
and you plan to wire it for freewheeling, the best switch to use is a double-
pole, double-throw (DPDT) “hesitation switch”— a toggle switch with
a mechanism that forces it to stop in the center (neutral) position before
going into the opposite direction. If a standard switch is moved quickly
from one direction to the other, it may not be in neutral long enough to
actuate HPD, and the motor will plug brake instead of freewheeling. The
switch must be in neutral for several milliseconds to actuate HPD.

8
Curtis PMC 1204/1205 Manual
HARDWARE INSTALLATION
Keyswitch
The vehicle should have a master on/off switch to turn the system off
when not in use. A keyswitch is typically used for this purpose.
Polarity Protection Diode
For polarity protection, a diode should be added to the control circuit.
This diode must be sized appropriately for the maximum total contactor
coil currents.
Control Wiring Fuse
To protect the control circuitry from accidental shorts, a small fuse
(typically 10 amps) connected in series with the B+ feed to the control
circuitry wiring is recommended.
Power Wiring Fuse
To protect the power wiring circuit, a fuse appropriate for the controller’s
rated current (see Appendix C) is recommended.

9
Curtis PMC 1204/1205 Manual
WIRING
CONNECTIONS: Low Current
Three 1/4" push-on terminals are provided
for the low current connections to the KSI
and throttle inputs.
For the control wiring, 0.75 mm2(#18
AWG) vinyl insulated stranded wire is rec-
ommended.
CONNECTIONS: High Current
Four tin-plated solid copper bus bars are provided for the high current
connections to the battery and motor:
M- output to motor field
B- negative connection to battery
B+ positive connection to battery and
to motor armature
A2 plug diode to motor armature
WIRING
3
KSI
throttle
inputs 3
2
1
A2
M-
B- B+
the high current required. A minimum size of 25 mm2(#4 AWG) is
recommended. Rubber insulated welding cable is convenient to work
with because of its flexibility.
Connections to the controller bus bars should be made with lugs
suitable for the cable used, fastened by M8 (5/16") bolts and nuts. When
tightening the bolts, two opposing wrenches should be used. Failure
to use the double-wrench technique could cause undue strain to be placed
on the internal connections, and could also result in cracked seals around
the bus bars.
The cables used for the battery and motor
connections must be heavy enough to carry

10
Curtis PMC 1204/1205 Manual
WIRING
Fig. 6 Basic wiring configuration,
Curtis PMC 1204/1205 controller.
WIRING: SERIES MOTORS
Figure 6 is a schematic of the configuration shown in Figure 5. Wired this
way, the vehicle will plug brake if the direction is changed with the vehicle
moving and the throttle applied. Reversing is accomplished via two single-
pole, double-throw (2×SPDT) contactors. Coil suppression diodes should
be used on the main and forward/reverse contactors.
KSI Wiring
The keyswitch input (KSI) circuit includes input from the keyswitch and
from the various interlocks. The controller KSI is used to turn the
controller on and off. KSI is turned on by connecting it to battery B+. Any
positive voltage greater than about 8 volts will turn on the controller, but
usually the full vehicle battery voltage is used. KSI draws only a very small
current (a few mA).
In its simplest form, KSI is operated by a keyswitch that turns the
vehicle off and prevents unauthorized use. The keyswitch should also
+
–
FORWARD
REVERSE
MAIN
FR
B- B+
M- A2
S2
A2
S1
A1
FR
FR
POTBOX
MAIN
KEYSWITCH INTERLOCKS
PEDAL
MICROSWITCH
CONTROL WIRING
FUSE
POLARITY
PROTECTION
DIODE
PRECHARGE RESISTOR
(250 Ω, 5 W)
POWER WIRING
FUSE

11
Curtis PMC 1204/1205 Manual
WIRING
turn off the main contactor and the forward/reverse contactors. This will
act as a safety feature by removing power from the motor control system
when the keyswitch is turned off.
Interlocks (seat switches, battery charger interlocks, etc.) should be
wired in series so that they turn off the controller KSI and the contactors.
Forward/Reverse Wiring (with standard power wiring)
These forward/reverse wiring schemes assume the standard power wiring
(shown by the heavy lines in Figure 6). Some vehicles, especially those
previously using older, resistor-type controllers, may reverse the motor
armature rather than the field winding. Be careful if you are replacing this
type of controller. When using the Curtis PMC controller it is essential
that the field be reversed and that the armature be connected directly
to the controller’s B+ and A2 terminals, because the plug diode inside
is connected to these terminals.
Plug braking
The standard forward/reverse control wiring (shown by the light lines in
Figure 6) provides plug braking. The forward/reverse switch should be in
the positive feed to the contactor coils, so that they can be turned off by
the keyswitch, interlocks, and pedal microswitch. The coil of one contactor
or the other is energized to select the direction desired.
Freewheeling (wiring to inhibit plug braking)
If your controller has the HPD option, this feature can be used to inhibit
plug braking by briefly turning off the controller’s KSI when the forward/
reverse switch goes through neutral. As shown in Figure 7, another set of
Fig. 7 Control wiring
for inhibiting plug
braking, in order to
allow freewheeling.
FORWARD
REVERSE
MAIN
KEYSWITCH INTERLOCKS PEDAL
MICROSWITCH
FUSE
POLARITY
PROTECTION
DIODE
B- B+
M- A2
F/R SWITCH
(DPDT, center off)
+
–

12
Curtis PMC 1204/1205 Manual
contacts is added on the forward/reverse switch. Therefore, a double-pole,
double-throw (DPDT) center-off switch must be used for this setup. A
“hesitation switch”is recommended, to ensure the switch is in neutral
long enough to actuate HPD and inhibit plug braking.
Plug braking can be reactivated during freewheeling by releasing the
throttle and reapplying it.
Forward/Reverse Wiring (with alternate power wiring)
The basic wiring scheme in Figure 6 shows reversing via two single-pole,
double-throw (2×SPDT) contactors. Your vehicle may be configured for
a different type of reversing. Two alternative power wiring schemes are
described below—reversing with four single-pole, single-throw (4×SPST)
contactors, and reversing mechanically rather than electrically.
Power wiring for reversing with 4 × SPST contactors
It is possible to use four single-pole, single-throw (4×SPST) contactors,
wired as shown in Figure 8. However, this configuration has the disadvan-
tage that if any one of the contactors sticks closed, the motor field is
effectively shorted out in one drive direction. The motor will not turn, and
it may be damaged if operated like this for long.
Other disadvantages are that four, rather than two, contactors must
be mounted and wired, and that the coils draw twice as much power. The
control wiring options for the 4×SPST contactors are the same as for the
2×SPDT contactors (see Figures 6 and 7).
As previously noted in the section on standard power wiring, when
using the Curtis PMC controller it is essential that the field be
reversed and that the armature be connected directly to the controller’s
B+ and A2 terminals, because the plug diode inside is connected to
these terminals.
Fig. 8 Power wiring
for reversing with
4 × SPST contactors.
WIRING
MAIN
PRECHARGE RESISTOR
(250 Ω, 5 W)
FUSE
B- B+
M- A2
FRS2S1
RF
+
–
A2 A1

13
Curtis PMC 1204/1205 Manual
Power wiring for mechanical reversing switch (golf car type)
As shown in Figure 9, this type of switch mechanically interchanges the
two motor field cables by rotating a movable contact bar. The configura-
tion shown is typical; many variations are in use.
Fig. 9 Power wiring
for reversing
with mechanical
forward/reverse
switch arm.
MAIN
PRECHARGE RESISTOR
(250 Ω, 5 W)
FUSE
B- B+
M- A2
S2
S1
+
–
A2 A1
WIRING

14
Curtis PMC 1204/1205 Manual
Throttle Pot Wiring
Standard potbox wiring
If the throttle input to the controller is from a Curtis PMC potbox or
footpedal, the wiring is simple: just connect the two wires of the potbox/
footpedal cable to the two push-on terminals of the controller, as shown
in Figure 6. It doesn’t matter which wire goes on which terminal. The
wires can be extended as required.
Any suitable potentiometer of 5 kΩnominal resistance will work
with the standard throttle input of the 1204/1205 controllers. As shown
in Figure 10, connection should be made to the wiper and to one outer
terminal of the pot so that resistance increases as the accelerator is applied.
Fig. 11 Bi-directional
twist-grip throttle with
10 k Ω center-tapped,
4-terminal pot.
which direction the twist grip is
turned. Alternately, a 4-terminal,
center-tapped 10 kΩpot can be
coupled directly to the twist grip,
as shown in Figure 11.
A third method of accom-
modating bi-directional twist grip
throttles uses a standard potenti-
ometer and a controller with a
Pots for twist-grip throttles
Twist grip throttles either twist in only one direction (and are used only
for acceleration), or they twist both ways (and are also used for reversing,
by means of microswitches that select a direction contactor). For twist
grips that twist in only one direction, the controller throttle input can be
from a 5 kΩpot as shown above in Figure 10.
For twist grips that twist both ways, a pot capable of going from zero
in neutral to 5 kΩin each direction can be used. A mechanism can be
designed to make a standard pot turn in the same direction regardless of
Fig. 10 Standard
throttle pot, 0–5k
Ω .
WIRING
TO
THROTTLE
INPUT
5 kΩ
5 kΩ
FASTER
FASTER
FASTER
TO
THROTTLE
INPUT
TO
THROTTLE
INPUT
FASTER
0–5kΩPOT
0–5kΩPOT