Watlow 935B User Manual

0600-0015-0001 Rev C $15.00

July 2000
Supersedes: 0600-0015-0001 Rev B

Registered Company

Winona, Minnesota USA

ISO 9001

TOTAL

3 Year Warranty

CUSTOMER

SATISFACTION

Series 935B

Temperature Controller

with Countdown Timer

1241 Bundy Boulevard, P.O. Box 5580, Winona, Minnesota USA 55987-5580

Phone: [phone], Fax: [phone], http://www.watlow.com

U.S. English

Now with Remote

Timer Start and

Fully DIN-a-mite

®

Compatible

User Levels:

• New User ...................................... Go to page 2

• Experienced User / Set-Up ........ Go to page 11

• Expert User ................................ Go to page 51

Installers:

• Mounting ..................................... Go to page 40

• Wiring Information .......................Go to page 44

Safety Information in this Manual

Note, caution and warning symbols appear throughout this book to draw your attention to
important operational and safety information.

A “NOTE” marks a short message to alert you to an important detail.

A “CAUTION” safety alert appears with information that is important for protecting your
equipment and performance.

A “WARNING” safety alert appears with information that is important for protecting you,
others and equipment from damage. Pay very close attention to all warnings that apply to
your application.

The ç symbol (an exclamation point in a triangle) precedes a general CAUTION or
WARNING statement.

The Ó symbol (a lightning bolt in a lightning bolt in a triangle) precedes an electric

shock hazard CAUTION or WARNING safety statement.

Technical Assistance

If you encounter a problem with your Watlow controller, review all configuration informa­tion to verify that your selections are consistent with your application: inputs; outputs;
alarms; limits; etc. If the problem persists after checking the above, you can get technical
assistance by calling your local Watlow representative (see back cover of this manual), or
in the U.S., dial [phone]. For technical support, ask for an Applications
Engineer.

Please have the following information available when you call:

• Complete model number • All configuration information

• User’s Manual • Diagnostic menu readings

Warranty and return information is on the inside back cover of this manual.

Your Comments

Your comments or suggestions on this manual are welcome. Please send them to the
Technical Literature Team, Watlow, 1241 Bundy Boulevard, P.O. Box 5580, Winona,
Minnesota, 55987-5580 U.S.; Telephone: [phone]; fax: [phone].

Copyright July 2000 by Watlow, Inc., with all rights reserved. (1950)

ç

Safety Alert

CAUTION or

WARNING

∫

Electrical Shock
Hazard

CAUTION or

WARNING

Watlow Series 935B User’s Manual 3

Where to find it…

Table of Contents

Item ............................................................. Page

Introduction ........................................................ 4

How Keys Work ................................................. 6

Begin Controlling ................................................ 8

Set Point Change ............................................... 9

Simple Error / Response ................................. 10

Software Map; Learn ........................................ 11

Operations Menu; Learn .................................. 12

PID Menu; Learn ...............................................14

Configuration Menu; Learn .............................. 18

Lockout Functions ............................................ 20

Setting Up Inputs and Outputs ........................ 22

Using Remote Timer Start Input .......................24

Front Panel Lockout ......................................... 25

Alarms; Learn ................................................... 26

Alarms; Setting and Clearing ........................... 28

Timer; Learn ..................................................... 30

Timer; Setting ................................................... 32

Timer Example ................................................. 33

Auto-tuning ....................................................... 34

PID Fine tuning ................................................ 35

Calibrating ........................................................ 36

Errors and Troubleshooting ............................. 38

Mounting ...........................................................40

Dimensions .......................................................41

Installing ............................................................42

Terminal Block Removal ...................................43

Wiring ............................................................... 44

Wiring Examples .............................................. 45

Glossary ........................................................... 46

Index ................................................................ 47

Specifications ................................................... 48

Ordering Information ........................................ 49

Declaration of Conformity ................................ 50

Advanced Software Map ...................................51

Warranty/Returns ................... Inside Back Cover

How to Reach Us .............................. Back Cover

Table # ..........................................................Page

1 Output Functions ....................................... 5

2 Error Messages & Action ....................... 10

3 Software Organization ............................ 11

4 Operations Menu Overview ................... 13

5 PID Menu Overview ............................... 16

6 Configuration Overview .......................... 18

7 Lockout Options ..................................... 21

8 Setting Inputs & Outputs ........................ 23

9 Using Front Panel Lock .......................... 25

10 Alarm Functions ..................................... 27

11 More Alarm Functions ............................ 29

12 Timer Functions/Settings ........................ 31

13 Possible Error Codes ............................. 39

14 Troubleshoot Outputs ............................... 39

15 Input Range Information ......................... 49

Figure # ........................................................Page

1 Input & Output Overview .......................... 5

2 Front Panel Functions .............................. 7

3 Begin Controlling ...................................... 8

4 Changing the Set Point ............................ 9

5 Front Panel Lock Wiring ......................... 25

6 Auto-tuning ............................................. 34

7 Calibrating .............................................. 36

8 Panel Cut-out Dimensions ..................... 40

9 Knockout Template ................................. 40

10 Dimensions ............................................ 41

11 Case Top View & Collar ......................... 42

12 NEMA 4X/IP65 Seal ............................... 42

13 Terminal Block Removal ........................ 43

14 Wiring ..................................................... 44

15 System Wiring Example ......................... 45

16 Ladder Diagram Example ...................... 45

4 Watlow Series 935B User’s Manual

Welcome to the Watlow Series 935B!

General Description

The Series 935B is a temperature controller with countdown timer for industrial, commercial, or scientific applications. It offers
1/32 DIN panel-mounting, digital indication, single temperature sensor input from a thermocouple or RTD, and dual control
outputs. Both outputs are fully DIN-a-mite®compatible, and may operate in combinations of heat or cool, and alarm or timer.

Special Features

• Easy to use operator interface and user’s manual

• Compact panel footprint; 1/32 DIN size

• Water and corrosion proof; NEMA 4X / IP65 rated

• Reliable; built to UL, CUL approved safety standards with a three year warranty

• Accuracy with economy

• Universal power supply for worldwide application

Unique Features

The Series 935B is configured with dual dc DIN-a-mite

®

compatible control outputs and a separate logic input for remote timer
start or front panel lock. The Series 935B timer functions include heat/timer or cool/timer countdown modes in hours:minutes or
minutes:seconds.

Introduction

Watlow Series 935B User’s Manual 5

Output 1

Output 2

RDY

2

1

SET

Single
Input

Dual Output

Single Input

Type J, K, T, N, S, E Thermocouple, 1° RTD, or 0.1° RTD

Output 1

Switched dc

Heat Cool Alarm

NONE

None

Heat Cool Alarm

30

15 45

0

Timer
(Hr:Min or
Min:Sec)

NONE

None

Output 2

Electromechanical Relay, Switched
dc or Solid-state Relay

Table 1 - Valid Output Functions

First select Output 1: Then select Output 2:

Heat None, Cool, Alarm, Timer

Cool None, Heat, Alarm, Timer

Alarm None, Heat, Cool

None Heat, Cool, Alarm

• The function of Output 1 determines
the options available for Output 2.

• First select the function of Output 1.
Refer to the table (right), then select
the function of Output 2.

Figure 1 - Series 935B Input and Output Overview

6 Watlow Series 935B User’s Manual

Press & read or press & change

Reading or Changing
Information is Easy

You can simply:

• Read the normally displayed actual temperature,
or…

• Press and hold ß to read the set point,
or…

1. Press and hold . and , simultaneously for three seconds to move to a software menu.

2. Press and hold ß to display a choice or value.

3. While continuing to press ß, press . or , to choose new data or select a new value.

4. Release ß and the arrow key to complete the change.

NOTE: The normally displayed actual temperature and set point can be altered to show different

combinations of actual temperature, set point temperature, or time in hours:minutes or minutes:
seconds. See [dISP] p. 18.

RDY

2

1

SET

Seven-segment
alphanumeric display:

• Shows process value,
set point information, time, or

• Shows prompt name or value,
depending on the key
combination pressed.

Set Key: ß

• Configurable to shift between
normally-displayed value and set
values. See [dISP], p.18.

• Clears a latched alarm.

LED 1:

Lit when Output 1 is active.

LED 2:

Lit when Output 2 is active.

RDY:

Lit when the process temperature
is inside the timer ready band.

Up / . (Increment)
Down / ,
(Decrement) Arrow Key:

• Selects new information when Set
Key is pressed.

• Steps through software menus and
parameters.

• Starts and stops the timer.

• To set up the control, go to the
Easy Software Map, p. 11.

Figure 2 - Series 935B Front Panel Functions

Watlow Series 935B User’s Manual 7

Begin Controlling

To Begin Controlling:

1. Apply power to the system.

A properly-wired Series 935B will begin controlling the thermal system as soon as you apply power
to it.

2. Look at the Series 935B’s display. It is reading actual temperature, set point temperature, or time.

• To change set point, go to p. 9.

• The Series 935B will auto-tune when you tell it to, go to p. 34.

• If you see an error, go to p. 10.

System

Power

RDY

2

1

SET

Figure 3 - Begin Controlling

8 Watlow Series 935B User’s Manual

Change Set Point

RDY

2

1

SET

To Change the Set Point:

Your Series 935B displays the actual process temperature when it comes from the factory. You can
change it to normally display the set point or time. Go to p. 18, see [dISP].

1. Press and hold ß.

2. Press one of the arrow keys to alter the set point either upward or downward.

3. Release ß to complete the change.

Figure 4 - Changing the Set Point

Watlow Series 935B User’s Manual 9

Respond to a simple error

Display Probable Cause Recommended Action

Reversed thermo- Change the sensor
couple connection leads on Terminals
+ to –. 1 and 2.

Sensor type Go to {`In} prompt, check
mismatch selection (see p. 22), or check
or open RTD. RTD, replace as necessary.

Sensor type Go to {`In} prompt,
mismatch. check selection

(see p. 22).

Open Thermocouple, Check the sensor,
bad connection, or replace as
broken wire. necessary.

Electrical noise. Cycle power to system. See if error

clears. Check system for electrical
interference.

Control is inoperable. Check for line voltage at

terminals 7 and 8.

RDY

2

1

SET

• Simply correct the cause.

• Errors are non-latching

and self-clearing.

• For advanced error and
troubleshooting
information, go to p. 39.

If You See An Error Code:

1. Be aware that most errors are input (sensor) related.

2. Read the table below and follow its recommendations.

Table 2 - Error messages and recommended action

[`Er1]

[`Er2]

[`Er3]

[`Er4]

[`Er5]

[````]

10 Watlow Series 935B User’s Manual

,

,

,

Watlow Series 935B User’s Manual 11

Software Organization

• The Series 935B has three primary menus in addition to a normal display.

• The software reverts to the normal display after 60 ± 5 sec. with no key action.

Table 3 - Software Organization

• To access the Operations Menu, press the

. and , keys simultaneously for three seconds.

• At the [`pid] or [Cnfg] prompt, press and hold the ß key, and the . or ,
key to select [`yes]. Release the keys to move to the new menu.

• Move through each menu with the . or , key.

• Make changes by pressing and holding the ß key, and

then the . or , key to select a new choice or
value. Release the keys to complete the change.

• To exit any menu: Press and hold the

. and , keys for three seconds,

or
the display will revert to normal display
after 60± 5 seconds.

Navigation Example

[Prnc] [Prno [dEnc [dEno

[`Ot2]

[disp]

[Alty]

,

Learn Easy Software Map

.

.

.

,,,,

ß

Display

Actual Temperature, Set Point, or Time Remaining

Operations, p. 12

Start / Stop:

•Autotune

Set:

•Alarm Ranges

•Countdown Timer

•Idle after Timer

Select
Set Point Type:

•Local / Remote

Go to:

PID Menu
Configuration Menu

[~yes]
[~yes]

PID, p. 14

Set:

•Heat PID Functions

•Dead Band

•Cool PID Functions

•Calibration Offset

Configuration, p. 18

Set:

•Inputs / Functions

•Output Types

•Display Default

•Alarms / Functions

•Timer Functions

•Failure Mode

•Lockout Functions

12 Watlow Series 935B User’s Manual

The Series 935B Operations Menu is the first menu you encounter when you press the . and , keys simultane­ously for three seconds. The Operations Menu provides a location to initiate the following actions or complete the
following tasks:

• Auto-tune [`Aut]: Start or stop the auto-tuning process. Auto-tuning selects a set of viable proportional, integral,

and derivative values for heat and/or cool output.

• Alarm Points, [`ALO] and [`AhI]: Select the values for the high alarm point and the low alarm point. Alarm points,

dependent on sensor type high and low ranges, reside in the Operations Menu for easy access.

• Timer Countdown Time [tMr]: Select a countdown time value between 00:00 and 99:59 hours:minutes or
minutes:seconds. Time interval choices [thM] and [tMS] reside in the Configuration Menu for Output 2.

• Idle Set Point [IDLE]: [trAc] or an adjustable value between [``rL] and [``rh]. Choose to have the Idle Set
Point track [trAc], or equal, the Primary Set Point; or select an Idle Set Point value in °F or °C between the range
low [``rL] and range high [``rh] values. The Idle Set Point is active both before and after the timing sequence.
The normal or Primary Set Point controls during the timing sequence.

• Go to the PID Menu [`Pid]: Choose [`YES] to proceed to the PID Menu.

• Go to the Configuration Menu [CnFg]: Choose [`YES] to proceed to the Configuration Menu.

The table on the next page presents this information in graphic form.

NOTE: Not every prompt listed here or on p. 13 in the Operations Menu will appear in your unit. Prompts vary
with lockout function and output set-up. Whether or not prompts appear in the Operations Menu depends on
two features of the Series 935B:

• Lockout function; the Lockout Tag [`tAg] function masks prompts from view in the various menus. (If you cannot
see a prompt, you can make no change.) See Using Lockout Functions, p. 20, for more information.

• Output 1 and 2 Configuration; some outputs are mutually exclusive. For example, if Output 1 is Alarm, then Output 2
cannot be Timer. Therefore, the Operations menu will have no timer-related prompts. See the Valid Output Functions
Table, p. 5, or Setting Up Inputs and Outputs, p. 22.

Learn the Operations Menu

Watlow Series 935B User’s Manual 13

Table 4 - Operations Menu Overview

To enter the Operations Menu, press the . and , keys simultaneously for three seconds.

Auto-tune - Start the auto-tune action to automatically select a set of viable PID values;

[tunE] will flash during auto-tuning.

[``no] [`YES]

NO YES

Alarm Low - Select a low alarm point,
adjustable between Off, Range Low and Alarm High.

[`AhI]

Alarm High

Alarm High - Select a high alarm point,
adjustable between Alarm Low and Range High, or OFF.

[`ALO]

Alarm Low

Countdown Timer - Select a countdown time duration.

[0)º0] [9959]

00:00 to 99:59 Hrs:Min or Min:Sec

Idle Set Point Type - Choose to track set point, or select a separate idle set point adjustable between
Range Low and Range High. When [`Ot1] = [thM] or [tMS], view the idle set point from the set point display
with a three second

ßpress.

[trAc] [``rL] [``rh]

Track Range Range
Set Low High
Point

PID Menu - Go to the PID Menu.

[``no] `YES]

NO YES

Configuration Menu - Go to the Configuration Menu.

[``no] `YES]

NO YES

[`Aut]

[`AhI]

[tmr]

[`Pid]

[CnFg]

[`ALO]

[IDLE]]

14 Watlow Series 935B User’s Manual

Choosing a PID Setting Strategy

You may rely solely on the Auto-tune [`Aut] function (p. 34) and factory defaults to determine PID values for your
system, or you may use auto-tuning and additional manual adjustments. You must select dead band [``db] and
calibration offset [`CAL] values manually.

The Series 935B PID Menu is the first sub-menu you encounter after moving to the Operations Menu. The PID Menu
provides a software location to select the individual heat or cool proportional band, hysteresis, and cycle time values;
and the dead band, integral, derivative, and calibration offset values.

To go to the PID Menu:

1. Go first to the Operations Menu by pressing

. and , simultaneously for three seconds.

2. Scroll through the Operations Menu with

, until you see the [`Pid] prompt.

3. While pressing ß to display [``no], choose [`YES] with . or

,.

4. Release ß to see the first PID prompt.

NOTE: Access to the PID Menu and the prompts there varies with lockout function and output set-up. The PID
Menu is locked out when the 935B leaves the factory.

• Lockout function; the Lockout Tag [`tAg] function masks menus from view (if you cannot see a prompt, you can

make no change).
See Using Lockout Functions, p. 20.

• Output set-up; you must choose [hEAt] or [COOL] in either Output 1 or Output 2 to have access to the PID Menu.
With a [hEAt] only choice, [COOL] prompts are not visible, and vice versa.

See the Valid Output Functions Table, p. 5, or Setting Up Inputs and Outputs, p. 22.

NOTE: Proportional Band, Integral, Derivative, Dead Band, and Calibration Offset values are adjustable in
whole or tenth °F or °C, depending on input type [``In] and [`C_F] Celsius/Fahrenheit Configuration Menu
choices.

Learn the PID Menu

Setting PID Menu Values

• Proportional Band, Heat and Cool [Pb`h] and [Pb`c]: Select a value (degrees) to set up band on either side (±)

of the Primary Set Point in which the heat and/or cool proportioning function(s) will be active.
For on/off control, set [Pb`h] or [Pb`c] = 0.

Range: 0 to 999°F/555°C, or 0.0 to 999.0°F/555.0°C
Default: 25°F/17°C, or 25.0°F/17.0°C

• Hysteresis, Heat and Cool [hYSh] and [hYSc]: For use with on/off control only. Select the value (degrees) for the

process variable change required to re-energize the control heat and/or cool output.
For ON/off control, set [Pb`h] or [Pb`c] = 0.

Range: 1 to 999°F/555°C, or 0.1 to 999.0°F/555.0°C
Default: 3°F/2°C, or 3.0°F/2.0°C

• Cycle Time, [Ct`h] and [Ct`c]: Select the value (seconds) required for the heat and/or cool output(s) to complete

a full ON through off cycle.

Range: Switched dc/Solid State Relay: 0.1 to 60.0 seconds
Default: 5.0 seconds
Range: Electromechanical Relay: 5.0 to 60.0 seconds
Default: 30.0 seconds

• Dead Band [``db]: Dead Band adjusts the effective cool set point above the primary set point by the Dead Band

value in degrees. This creates a band between the heating and cooling proportional bands where only integral and
derivative activity will occur. For more information on Dead Band fine tuning, go to p. 35.

Range: 0 to 999°F/555°C, or 0.0 to 999.0°F/555.0°C
Default: 0°

• Integral [``It]: Select a value (minutes/repeat) for the integral function. Integral is the inverse of Reset; It(value) =

1/Reset(value).

Range: 0.00 to 99.99 minutes/repeat
Default: 5.00 minutes/repeat

• Derivative [``dE]: Select a value (minutes) for the derivative function.

Range: 0.00 to 9.99 minutes
Default: 0.00 minutes

• Calibration Offset [`CAL]: Eliminates the difference between the displayed process temperature and the actual

process temperature value.

Range: -999 to 9999°F/C, or -99.9 to 999.9F/C
Default: 0°

Watlow Series 935B User’s Manual 15

16 Watlow Series 935B User’s Manual

Table 5 - PID Menu Overview

Set-Up Heat

Proportional Band Heat - Select a heat proportional band value.

[```0] [`999] [```0] [`555] [``)0] [99(0] [``)0] [55%0]

0°F to 999°F, or 0°C to 555°C, or 0.0°F to 999.0°F, or 0.0°C to 555.0°C

Hysteresis Heat - Select a heat ON/off control switching hysteresis.

[```1] [`999] [```1] [`555] [``)1] [99(0] [``)1] [55%0]

1°F to 999°F, or 1°C to 555°C, or 0.1°F to 999.0°F, or 0.1°C to 555.0°C

Cycle Time Heat - Select a heat output cycle time.

[``)1] [`6)0] [``%0] [`6)0

0.1 to 60.0 seconds 5.0 to 60.0 seconds
(SSR or Switched dc) (Electromechanical Relay)

Dead Band - Select a dead band value.

[```0] [`999] [```0] [`555] [``)0] [99(0] [``)0] [55%0]

0°F to 999°F, or 0°C to 555°C, or 0.0°F to 999.0°F, or 0.0°C to 555.0°C

Set-Up Cool

Proportional Band Cool - Select a cool proportional band value.

[```0] [`999] [```0] [`555] [``)0] [99(0] [``)0] [55%0

0°F to 999°F, or 0°C to 555°C, or 0.0°F to 999.0°F, or 0.0°C to 555.0°C

Hysteresis Cool - Select a cool ON/off control switching hysteresis.

[```1] [`999] [```1] [`555] [``)1] [99(0] [``)1] [55%0

1°F to 999°F, or 1°C to 555°C, or 0.1°F to 999.0°, or 0.1°C to 555.0°C

Cycle Time Cool - Select a cool output cycle time.

[``)1] [`6)0] [``%0] [`6)0

0.1 to 60.0 seconds 5.0 to 60.0 seconds
(SSR or Switched dc) (Electromechanical Relay)

[Pb`h]

[hySh]

[Ct`h]

[``db]

[Pb`c]

[hySc]

[Ct`c]

Learn the PID Menu - Details

Watlow Series 935B User’s Manual 17

Set-Up General

Integral Function - Select an integral value.

[`)00] [9(99]

0.00 to 99.99 minutes/repeat

Derivative Function - Select a derivative value.

[`)00] [`(99

0.00 to 9.99 minutes

Calibration Offset - Select a calibration offset value.

[-999]] [9999] [-9(9] [99(9

-999° to 9999°F or C or -99.9° to 999.9°F or C

NOTE: Access to the PID Menu and the prompts there varies with lockout function and output set-up. The PID
Menu is locked out when the 935B leaves the factory.

• Lockout function; the Lockout Tag [`tAg] function masks menus from view (if you cannot see a prompt, you can

make no change). See Using Lockout Functions, p. 20.

• Output set-up; you must choose [hEAt] or [COOL] in either Output 1 or Output 2 to have access to the PID Menu.
With a [hEAt] only choice, [COOL] prompts are not visible, and vice versa. See the Valid Output Functions Table,
p. 5, or Setting Up Inputs and Outputs, p. 22.

[``It]

[``dE]

[`CAL]

18 Watlow Series 935B User’s Manual

The Configuration Menu is the second sub-menu in the Operations Menu. Use it to set Inputs, Ranges, Output Types,
Alarms, Timer, Failure Mode, and Lockouts.

To go to the Configuration Menu:

1. Go first to the Operations Menu by pressing . and , simultaneously for three seconds.

2. Scroll through the Operations Menu with , until you see the [CnFg] prompt.

3. While holding ß to display [``no], choose [`YES] with . or ,.

4. Release ß to see the first [CnFg] prompt, [``In].

5. To leave the Configuration Menu, press . and , for 3 seconds.

Table 6 - Configuration Menu Overview

Input Type - Choose sensor type. See p. 23 for sensor ranges.

[```J] [```H] [```t] [```n] [```E] [```S] [`rtd] [`r†d]

J t/c K t/c T t/c N t/c E t/c S t/c 1.0° RTD 0.1° RTD

Celsius/Fahrenheit - Choose displayed unit of measure.

[``°F] [``°C]

°F °C

Input Range Low - Select lowest displayable set point. Ranges, p. 23.

[``In] [``rh]

Select a value (lowest displayable set point) between Input Type Range Low and Input Range High.

Input Range High - Select highest displayable set point. Ranges, p. 23.

[``Rl [``In]]

Select a value (highest displayable set point) between Input Type Range High and Input Range Low.

Output 1 Function - Choose Output 1 type; see Valid Outputs Table, p. 23

[hEAt] [COOL] [ALM] [nonE]]

Heat Cool Alarm None

Output 2 Function - Choose Output 2 type (dependent on Output 1 choice).

hEAt] [COOL] [ALM] [thM] [tMS] [nonE]

Heat Cool Alarm Timer Timer None

Hr./Min. Min./Sec

Remote Timer Start - Choose remote timer start operation.

[`off] [`fpl] [tmr]

Off Front Panel Countdown

Lock Timer

Display Default -

Choose the primary (last 2 characters) and secondary (first 2 characters) default displays. Press ßto toggle to the

secondary display for 15 seconds.

[``Ac] [AcSP] [Acti] [tiAc] [tiSP]

No secondary Actual temp. Actual temp. Time remaining Time remaining
Actual temp. Set pnt temp. Time remaining Actual temp. Set point temperature

Alarm Type - Choose alarm type with output action.

[Prnc] [Prno] [dEnc] [dEno]

Process Process Deviation Deviation
normally normally normally normally
closed open closed open

[``In]

[`C_F]

[``rL]

[``rh]

[`Ot1]

[`Ot2]

[dISP]

[ALty]

Learn the Configuration Menu

[`rts]