Curtis 1204, 1205 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.

If you would like a hard copy of the published manual, please order it by part number from
the Curtis office nearest you.

The electronic version of the manual is identical to the printed version published in May

1999. Bookmarks have been added to the electronic version to speed the process of going
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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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 kΩ center-tapped, 4-terminal pot ............................. 14

FIG. 12 Bi-directional twist-grip throttle with

20 kΩ pot and controller with optional

5kΩ–0 throttle input ..................................................... 15

FIG. 13 Reduced speed operation (with standard 0–5kΩ pot).... 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

2

HARDWARE 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 dimen­sions 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 self­contained footpedal unit (FP-2) that eliminates the need for fabricating
and installing a pedal-potbox linkage. Any potbox that provides a nominal

0–5kΩ output (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 self­contained 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 ohm­meter. 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 installa­tion 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 CONTACT OR

(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 sole­noid 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 double­pole, 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 rec­ommended.

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