Watlow Micro-Based Autotuning Control SERIES... User manual

Microprocessor-Based
Auto-tuning Control
( User’sManual)
Watlow Controls, 1241 Bundy Blvd., P.O. 8ox 5580, Winona, MN 55987-5580, Phone: [phone], Fax: [phone]
W985-MA58-9307
February, 1993
Supersedes:
W985-MA70-9043
$10.00
Made in the U.S.A.
0
0 Printed on Recycled Paper

How to Use the Manual
First..
StartingOut
Install/Wire
Front Panel
Set Up
Tuning
Appendix
NOTE:
Details of a *‘Note**
appear here, in the
narrow box on the
outside of each page.
LLL
CAUTION:
Details of a “Caution”
appear here, in the
narrow box on the
outside of each page.
0
WARNING:
Details of a “Warning”
appear here, in the
narrow box on the
outside of each page.
This manua/ will make your job easier.
Reading it and applying the informa-
tion is a good way to become familiar with the Series 980/985.
An overview:
Chapter 1, Page 4.
Chapter 2, Page 6.
Chapter 3, Page 22.
Chapter 4, Page 24.
Chapter 5, Page 29.
Specifications, Page 34
Cali bration
Glossary
Warranty
Notes
The user’s manual contains informational notes to alert you to important details.
When you see a note icon, look for an explanation in the margin.
1 orJ3
Safety Information
This user‘s manual also hasboldface safety information notes to protect both
you and your equipment. Please be attentive to them. Here are explanations:
A
T
The Caution symbol (exclamation point) in the wide text column alerts you to a
“CAUTION,” a safety or functional hazard which could affect your eguipment or
its performance. A full explanation is in the narrow column on the outside of
the page.
0
The Warning symbol (lightning bolt) in the wide text column alerts you to a
**WARNING,” a safety hazard which could affect you and the equipment. A full
explanation is in the narrow column on the outside of the page.
Your Feedback
Your comments or suggestions on this manual are welcome, please send them
to: Technical Writer, Watlow Winona, Inc., 1241 Bundy Blvd., Winona, MN
55987, or phone [phone]. The Watlow Series 9801985 User’s Manual
and integral software are copyrighted by Watlow Winona, Inc., © 1988, with all
rights reserved.
blrO293
2
WATLOW Series 9801985 User’s Manual
How to Use the Manual

Chapters
Figures, Table, Charts
page
Item
page
Item
4Starting Out With The Watlow Series 980/985
4 General Description
5
Putting Your Control To Work
5
Overview of the Series 980/985 Menus
Chapter 2
6
6
6
6
7
9
9
10
11
13
21
How To Install And Wire The Series 980/985
System Planning
Sensor Installation Guidelines
Installation Guidelines For Preventing Noise
Noise
Checking For Ground Loops
Noise Suppression Devices Available..
Line Filtering Configurations For Controls
How To Install The Series 980/985
How To Wire The Series 980/985
System Wiring Example
22
22
23
Chapter 3
How To Use The Keys and Displays -
Series 980/985 Displays & Load LED’s
Series 980/985 Keys
24
24
25
26
27
28
Chapter 4
How To Set Up The Series 980/985 -
Entering Set Up Menu
Set Up Parameters
Set Up Menu
Operation Parameters
Operation Menu
29
29
30
31
31
32
Chapter 5
How To Tune And Operate -
Tuning - Manual
Tuning - Automatic
Manual and Automatic Operation
Using Alarms
How To Deal With Error Codes
34 Appendix
34 Specifications
36 Model Number Information
37 Calibration Menu
38 Calibration Procedures
38 Glossary
41 Index
42 Returns
42 Shipping Claims
43 Warranty
43 Watlow Controls
Chapter 1
Figure
4
5
10
10
10
12
12
13
13
14
14
15
15
16
16
l?
17
18
18
19
19
20
20
21
22
23
24
24
27
31
32
37
38
Series 980/985
Input & Output Overview
1
Overview of the
Series 980/985
2
Differential Mode Filter Wiring
3
Common Mode Fifter Wiring
4
Combination filter Wiring
5
Series 980/985 Panel Cutout Dimensions
6
Series 980/985 Dimensions
7
115 VAC Power Wiring
8
230 VAC Power Wiring
9
Thermocouple Wimg Diagram
10
Process Wiring Diagram
11
RTD (2 wire) Wiring Diagram
12
RTD (3 wire) Wiring Diagram
13
Solid State Relay, Output 1 Wiring
14
DC Output 1 (Open Collector) Wiring
15
6 Amp Relay, Output 1 Wiring
16
O-lOVDC, Output 1 Wiring
17
4-2OmA, Output 1 Wiring
18
O-2OmA, Output 1 Wiring
19
0-5VDC, Output 1 Wiring
20
S.S. Relay, Output 2 Wiring
21
DC Output, Output 2 Wiring
22
6A Mechanical Relay, Output 2 Wiring
23
System Wiring Example
24
Series 980/985 Displays
25
Series 980/985 Keys
26
Entering the Set Up Menu
27
The Set Up Menu
28
The Operation Menu
29
Alarm Display Examples
31
Error Code Display Examples
32
The Calibration Menu
33
Calibration Parameters
34
9 Noise Suppression Device Ratings
39 RTD Settings
26 Set Up Menu Prompts/Description
26 Input Ranges
28 Operation Menu Prompts/Description
Tables
1
2
Charts
1
2
3
How to Use the Manual

Chapter 1
Flgure 1 -
Series 980/985 Input
and Output Overview
Starting Out With The
Watlow Series 9801985,
A Microprocessor-Based Control
SingleInput -
Type J, K, T, N or Pt2
Dual Outputs-
PID or ON/OFF
User Selectable
Heat, Cool or Alarm
Output 1 or 2
Percent Power
Output 1, Heating
Auto-tuning
General Description
Welcome to the Watlow Series 980/985, a dual output, single input, micropro-
cessor-based, 1/8 DIN, auto-tuning temperature control, featuring the Auto-
matic/Manual capability with bumpless transfer. In the Auto mode, the control
has closed loop control with sensory feedback, while the Manual mode has
open loop control with user defined output power level.
The 980/985 accepts
a Type J, K, T, N, or Platinel2 thermocouple, RTD, or process input. The
primary output is Heating or Cooling, while the secondary output can be Heat,
Cool or Alarm.
With the Series 980/985 you can select either PID or ON/OFF for Output 1 or
Output 2. You may input a complete set of PID parameters for both outputs,
and select automatic tuning for Output 1 from the front panel. This includes
proportional band, reset, rate and cycle time. By setting either output’s propor-
tional band to zero, the Series 9801985 becomes a simple ON/OFF control with
a 3°F or 1.7°C switching differential, 0.3°F or 0.17°C for 0.1 ° RTD.
Operator-friendly features include automatic LED indicators to aid in monitoring
and set-up, as well as a calibration offset at the front panel. The Watlow
Series 980/985 automatically stores all information in a non-volatile memory.
4 WATLOW Series 980/985 User’sManual
GettingStarted, Chapter 1

Putting Your Control To Work
To put your Series 980/985 to work, we suggest the following steps:
Read the User’s Manual.
Plan your installation and wiring.
Cut the panel mounting hole and install the control.
Wire your Series 980/985 to the system.
Start the system and tune the Series 980/985.
Make final adjustments to the control parameters and record the data.
That’s all there is to it.
Overview of the Series 980/985 Menus
Before getting into the details of installing and wiring the Series 980/985, take a
look at Figure 2, and at the three different menus. “Setup”, “Operation”, and
“Calibration”. After you feel comfortable with the names and their functions,
move on to installation and wiring.
Setup
Operation
Calibration
Configure the 980/985’s features to your
application. Establish levels of operator
access, input type, units of measure, low and
high range limits, and Output 2 configuration.
Figure 2 -
Overview of the
Series 980/985.
Enter the set point and the PID tuning values
and alarm set points here. Parameters for
proportional band, reset, rate and cycle time for
Outputs 1 and 2; alarm low and high; dead-
band: calibration offset and auto-tune
are here also.
Supply various input signals to the
Series 980/985, and it performs auto-
calibration. Calibration procedures
should only be attempted with
proper equipment and by qualified
personnel.
Where To Go From Here
If your Series 980/985 is already installed and wired, go directly to “How to Use
the Keys and Displays”, Chapter 3. If not, turn the page to Chapter 2, “How to
Install and Wire the Series 980/985”, and proceed from there.
Getting Started, Chapter 1
WATLOW Series 980/985 User’s Manual

Chapter 2
How to Install and Wire the
Series 9801985
SystemPlanning
Thischaptertellsyouhowtoinstallthe Series 980/985. Allmountingand
wiring information is right here.
Because Watlow controls are thoroughly
tested and "burned in" before leaving the factory, the Series 980/985 is ready
to install when you receive it.
But before you begin working, read through this chapter to gain an understand-
ing of the entire installation. Consider sensor installation carefully. You’ll need
to look at the noise reduction guidelines before making your panel cutout.
SensorInstallationGuidelines
We suggest that you mount the sensor at a location in your process or system
where it reads an average temperature.
Put the sensor as near as possible to
the material or space that you want to control. Air flow past this sensor should
be moderate. The sensor should be thermally insulated from the sensor
mounting.
Installation Guidelines For Preventing Noise
For improved electrical noise immunity, install the Series 980/985 as far away
as possible from motors, relays, and other similar noise generators.
Do not run low power (sensor input) lines in the same bundle as AC power
lines. Grouping these lines in the same bundle can create electrical noise
interference which may result in error codes in the Series 980/985.
The Culprit
Most noise problems stem from wiring practices. They’re the major means of
coupling noise from its sources to the control circuit The following information
will tell you how to eliminate or decrease noise.
An Information Resource
Anoutstandingresource for information for wiring guidelines is the IEEE
StandardNo. 518-1982 and is availablefrom IEEE, Inc.345 East 47thStreet,
New York, NY 10017.
6 WATLOW Series 980/985 Users Manual
Install and Wire, Chapter 2

Noise Sources
Switchesandrelay contacts operating inductiveloadssuchas motor, coils,
solenoids, and relays, etc.
Thyristors or other semiconductor devices which are not zero crossover-fired
(randomly-fired or phase angle-fired devices).
All welding machinery.
Heavy current carrying conductors.
Fluorescent and neon lights.
How To Decrease Noise Sensitivity
Physical separatlon and wire routing must be given careful consideration in
planning the layout of the system. For example, A.C. power supply lines
should be bundled together and physically kept separate from input signal
lines(sensorlines).A12inchminimumseparatlonisusuallyeffective . Keep
all switched output signal lines (high power level) separate from input signal
lines (sensor lines). Cross other wiring at 90° angles whenever crossing lines
is unavoidable.
Another important practice is to look at the system layout and identify electri-
cal noise sources such as solenoids, relay contacts, motors, etc., and where
they are physically located. Then route the wire bundles and cables as far
away as possiblefrom these noise sources.
Don’t mount relays or switching
devices close to a microprocessor control. Don’t have phase angle-fired
devices in the same electrical enclosure or on the same power line with the
control.
Shielded cables should be used for all low power signal lines to protect from
magnetic and electrostatic coupling of noise. Some simple pointers are:
• Whenever possible, low level signal lines should be run unbroken from
signal source to the control circuit.
• Connect the shield to the control circuit common at the control end only.
Never leave the shield unconnected at both ends. Never connect both
shield ends to a common or ground.
• If the shield is broken at some termination point and then continued on, the
shield must be connected to maintainshieldcontinuity.
• If the shield is used as a signal return, no electrostatic shieldlng should be
assumed. If this must be done, use a triaxed cable (electrostatically
shielded coaxial cable).
Twisted pair wire should be used any time control circuit signals must travel
over two feet or when they are bundled in parallel with other wires.
The size or gauge of wire should be selected by calculating the maximum
circuit current and choosing the gauge meeting that requirement. Using
greatly larger wire sizes than required generally will increase the likelihood of
electrostatic (capacitance) coupling of noise.
Install and Wire, Chapter 2
WATLOW Series 980/985 User's Manual
7

• Groundloops mustbe eliminatedin the entirecontrolsystem. There are
obvious loops which can be spotted by studying the"as-built" wiring diagram.
There are also the not-so-obvious ground loops that result from the technique
of connecting internal circuit commons in the manufacturer's equipment. An
example of this would be if a control circuit is designed to work with a
groundedsensorinput.
• Do not daisy chain A.C. power (or return) lines, or output signal (or return)
lines to multiple control circuits.
Use a direct line from the power source to
eachinputrequiring A.C.power.Avoidparalleling L1 (power lead)and L2
(return lead) to load power solenoids, contactors, and control circuit
ts.
If L1
(power lead) is used to switch a load, L2 (return lead) willhave the same
switched signal and could couple unwanted noise into a control circuit.
• Grounding the chassis of each piece of equipment in the system is very
important. The simple practice of connecting each individuai chassis to the
overall equipment chassis immediately adjacent to that piece, and then tie all
the major chassis ground terminals together with one lead (usually green
wire) to ground at one single point will work best.
Don’tconnectgroundto
the control case if the control is mounted in grounded enclosure (prevent
ground loops).
• Do not confuse chassis grounds (safety ground) with control circuit commons
or with AC. supply lines L2 (return or neutral line).
Each return system
wiring must be kept separate. Be absolutely sure chassis ground (safety) is
never used as a conductor to return circuit current
How To Eliminate Noise
• Use “snubbers” ("QUENCHARC™") to filter out noise generated by devices
such as relays, relay contacts, solenoids, motors, etc. A snubber is a simple
filter device using a 0.1µ
f, 600 volt, non-polarized capacitor in series with a
100 ohm, 1/2 watt resistor. The device can be used on A.C. or D.C. circuits
to effectively dampennoiseatitssource.
• The general purpose Watlow snubber, described above, is 0804-0147-0000.
For other ‘QUENCHARC” sizes contact
PAKTRON
P.O.Box5438
Lynchburg,VA24502
Phone: [phone]
• Metal Oxide Varistor (MOV) can beused tolimit voltage“spikes” that
occur on the A.C. supply lines as a result of lightning strikes, switching large
motors, etc. The MOV is available in several varieties and for 115 or 230
volt lines. The
device dissipates the voltage “spikes” to ground and in doing
so repeatedly, deteriorates its ability to function. MOVs havealimitedlife.
• Watlow stocks several MOVs. See Table 1.
8 WATLOW Series 980/985 User's Manual
Install and Wire, Chapter 2

"Islatros" andother similarpowerlinefiltersaredesignedto carry thepower
for the control circuit and “buffer” the control circuit from A.C. line noise.
Devices like the lslatrol use media (electromagnetic filtering) other than
electric circuits to filter out electrical noise. Take care in matching the power
capabilities of the filter with power demands of the circuit.
Keepline filters as
close to the control as possible to minimize the area for interference pick up.
lslatrols are availablefrom: ControlConcepts Corporation
328 Water Street
P.O.Box 1360
Blnghamton, NY 139O2-1360
Phone: [phone]
I - 101 (1A,l20VAC) I - 202 (2.5A, 208/240VAC)
I - 105 (5A, 120VAC) I - 207 (7.5A, 208/240VAC)
I - 115 (15A, 120VAC)
The ultimate protection is an “uninterruptable” power supply. This 'senses'
the A.C. power line; when the line fluctuates, a battery powered 6OHz in-
verted circuit takes over, supplying power within one-half to one cycle of the
A.C. line; very expensive.
How To Check For Ground Loops
To check for ground loops, disconnect the ground wire at the ground termina-
tion. Measure the resistance from the wire to the point where it was connected.
The ohmmeter should read a high ohm value. If you have a low ohm value
across this gap, there is at least one ground loop present in your system.
Or check for continuity; your reading should be "open”.
Ifyoudofind continu-
ity, you must now begin looking for the ground loops. Begin disconnecting
grounds in the system one at a time, checking for continuity after each discon-
nection. When continuity reads "open” you have eliminated the ground loop(s).
Also, as you reconnect grounds, keep making the continuity test. It is possible
to reconnect a ground loop.
Noise Suppression Devices Available From Watlow
Watlow Controls stocks a few key noise suppression parts. You may order
these by calling your localWatlowdistributor.
Item
Electrical Ratlngs Part Number
Common Mode Line Filter
25OV, 3 Amp 0804-0196-0000
Differential Mode Line Filter
Refer to the lslatrol listing above.
Metal Oxide Varistor
15OV, 80 Joule
0802-0273-0000
MOV
13OV,38 Joule 0802-0304-0000
802-0304-0000
MOV
275V, 75 Joule
0802-0266-0000
MOV
275V, 140 Joule
0802-0405-0000
Table 1 -
NoiseSuppressIon
Device Ratings
Install and Wire, Chapter 2
WATLOW Series 98O/985 User’sManual
9

Line Filtering Configurations For Controls
Figure 3 -
These three diagrams show you filter configurations for removing input power
noise. Choose the one best suited for your system.
Forverydirtyor critical
applications - use a microcomputer-regulatedpowersupplyor Uninterruptable
Power Supply(U.P.S.)
Don’t fasten common mode line filters or filters with
metal cases to metal that is at ground potential. This prevents ground loops
and maintains filter effectiveness.
Differential Mode
Filter
Wiring
Ll
D.M. Line Filter
.
NOTE: Keep filters
12 inches or less
from the control.
Minimize the line
distance where
nolse can be re-
introduced to
control.
Control
Common Mode Filter
Wiring
2
NOTE: To prevent
ground loops do not
fasten common
mode line filters or
filters with metal
cases to metal that
is at ground poten-
tlal. Doing so will
reduce filter effec-
tiveness.
Figure 5 -
Combination
Differential/
Common Mode Filter
Wiring
C.M. Line Filter
Control
I
Ground
Control
10 WATLOW Series 980/985 User's Manual
Install and Wire, Chapter 2

How to Install the Series 980/985
Figures 6,7 and 8 provide the Series 980/985’s panelcutoutanddimensions.
Do not, however, make your panel cutout until you are sure that you are
placingthe control in the best location. Read the noise guidelines at the
beginning of this chapter before installing and wiring the Series 980/985.
1.
2.
3.
4.
5.
6.
7.
8.
9.
Place the panel cutout in the desired location.
Figure 6 shows you the
panelcutoutdimensions.
Toinstall, carefully insert the Series 980/985 intothepanelcutout.
Push
1
NOTE:
the unit in until the bezel is seated securely against the panel.
Removing the Series
980/985 chassis
Included with your control are two adjustable mounting brackets; one for the
top and one for the bottom of the control case.
Installingthemounting
from its case may
make mounting
brackets requires access to the back side of the panel.
On the top and bottom of the case are a series of slots running the length of
the case. The first two shorter slots are for attaching the mounting brack-
ets. Figure 8 shows a side view with both mounting brackets.
easier.
Loosen the mounting bracket screws with a Phillips screwdriver far enough
to allow for the panel thickness.
Make sure that each bracket is placed in the first two slots from the front of
the control, with the head of the screw facing the back of the control.
Refer
to Figure 8 for screw and bracket placement.
To attach, place the bracket into the slots (head of the screw facing the
back of the control and push backward, securing the brackets to the control
case.
Do the same for the other side of the control.
Make sure the Series 980/985 case is seated properly. Tighten the installa-
tion screws firmly against the panel to secure the unit in place.
To remove the unit from its enclosure, loosen the captive screw at the
bottom of the 980/985’s front panel with a Phillips screwdriver.
Pulltheunit
from its case.
To release the mounting brackets, push the brackets forward and pull out to
release them from the control case.
Installand Wire, Chapter 2
WATLOW Series 980/985 User’s Manual 11

Figure 6 -
Series 980/985
Panel Cutout
Dimensions
Panel Cutout
Max.Panel
Thickness
0.50 (12.7mm)
~
3.82 +0.03 - 0.00
(92mm + 0.8)
LoadPower
indicators V
Panel
T
I .89
(48.0 mm
Figure 7 -
Series 980/985
Dimensions
_ Adjustuble
12 WATLOW Series 9801985 User’s Manual ‘Install and Wire, Chapter 2

How to Wire the Series 980/985
The Series 980/985 wiring is illustrated by model number option. Check the
unit sticker on the control and compare your model number to those shown
here and also the model number breakdown in the back of this manual.
Series 980/985 internal circuits appear “inside“ the line drawing of the 980/985,
while connections and terminal designations appear “outside” the line drawing.
All outputs are referenced to a de-energized state. The final wiring figure is a
typical system example.
All wiring and fusing should conform to the National Electric Code and to any
locally applicable codes as well
.
When you apply power without sensor inputs on the terminal strip, the Series
980/985 will display “- -
” - in the Upper display, and a "O" in the Lower display.
Press the AUTO/MANUAL key twice, and an ER 7 is displayed for one second.
This error indicates an open sensor. Remove power to the control and connect
the sensor properly, see Page 14.
II II
Jumper #4 to #6 and
Jumper #5 to #7 for
115 VAC operation
0
II 0
Jumper #5 to #6 for
230 VAC operation
L2
Earth
Ground
Figure 8 -
115 VAC Power
Wiring
0
CAUTION:
To avoid potential
electric shock, use
National Electric
Code (NEC) safety
practices when
wiring and connect-
ing this unit to a
power source and to
electrical sensors or
peripheral devices.
Figure 9 -
230 VAC Power
Wiring
Install and Wire Chapter 2
WATLOW Series 980/985 User’s Manual
13

Figure 10 -
Input Options “1”,
**2* & *3’, Thermo-
couple Wiring
Diagram.
Flgure
11 -
Input Options "2" &
"3" Process Input
Wlring Diagram.
1
NOTE:
When using a 4-
2OmA process
Input, the input
impedance is
2 4 9 o hms
lnput Options “1
“, “2” & “3”, Thermocouple Input
Terminals 18 & 20
Model # 98
– A - 1 _ _ - 0-0000
98_A-2 – – 0-0000
98_A-3- 0-0000
– –
II II
I
1
NOTE:
You must use an isolated or ungrounded thermocouple if an external 4-20mA
output device with a non-isolated circuit common is connected to the 4-20mA
output.
Extenslon wire for thermocouples must be of the same alloy as the thermocouple
itself to limit errors.
These input connections are used in conjunction with your units sensor
type. (Thermocouple and RTD only)
Input Options “2’ & “3”, Process or Remote Set Point Input
Terminals 15 - 17
Model #98_A - 2 _ _ 0 - 0000
98_A - 3 _ _ 0 - 0000
0 II
Jumper Terminal 16
to Terminal 17 when
using a 4-20mA
input.
.
fl
0-5VDC 4-20mA INPUT
16
17 0-5VDC, 4-20mA INPUT
Input
Voltage
J3
NOTE:
When using a process input such as O-5VDC or 4-2OmA, the rL and rH settings
scale the display to match the measured range of the process signal. When using
a 0-5VDC process input, the input impedance is 100K ohms.
An example of this is: A pressure transducer operates over a range of 0 - 300 PSI,
delivering a 4-20mA output signal for this range. By setting rL=0 and rH = 300,
the Series 980/985 is now displayed as a direct reading of pressure.
14
WATLOW Series 980/985 User’s Manual
Install and Wire, Chapter2

Input Options “2” & "3" RTD - 2 Wire
Terminals 12 - 14
ModeI#98 _A-2_ _0-0000
98_A-3_ _0-0000
Jumper#l3to#l4
II II
.
.
.
.
.
.
Input Options “2” & "3" RTD - 3 Wire
Terminals 12 - 14
Model# 98_ A-2_ _ 0-0000
98_A-3_ _0-0000
.
.
.
.
.
.
-
J
NOTE:
Long lead lengths create electrical resistance. There will be a S 1° approximate
input error for every 1ohm of lead length resistance when using a two wire RTD.
That resistance, when added to the resistance of the RTD element, can result in
erroneous input to the instrument. To overcome this problem, use a three wire
RTD sensor, which compensates for lead length resistance. When extension wire
is used for a three wire RTD, all three extension wires must have the same
electrical resistance. (i.e. same gauge, copper stranded).
Figure 12
-
Input Options "2" &
“3”, RTD (2 wire)
Sensor Wiring.
Figure 13 -
Input Options “2’ &
‘*3”, RTD (3 wire)
Sensor Wiring.
Install and Wire, Chapter 2
WATLOW Series 980/985 User's Manual
15

Output 1 Option “B”, Solid State Relay
Figure 14 -
Solid State Relay,
Output 1, Option “B”
Wiring Diagram.
Figure 15 -
DC Output 1 (Open
Collector), Option
72” Wiring Diagram.
ModeI# 98_A-_ B _0-0000
Solid State
Relay
Solid State Relay
Watlow's solid state relays change state at zero volts, which is *zero-cross switching.”
They are also optically isolated, which means the output circuitry is energized by
infrared light striking a photo-sensitive device. This results in virtual absence of electri-
cally generated noise, pIus output to input electrical isolation. Off state impedance is
2O Ko hm minimum.
Output 1 Option “C”, DC Output (Open Collector)
Model# 98_A-_C_0-0000
71 +
,
.
3 -Q
DCLoad
.
.
.
.
.
.
.
-
u
Switched DC
Watlow’s solid state switch isa low current DC output (open collector) used to switch an
external power switching device such as an SSR or an electromechanical relay. The
input specifications of the power switching device must those listed for the SS
switch output. The power switching device must provide isolation between the SS
switch output and load power since the SS switch output is a non-isolated output.
Minimum load resistance is 5OO o hms. Available current is minimum 9mA, 22mA maximum.
16
WATLOW Series 980/985 User’s Manual Install and Wire, Chapter 2

Output 1 Option “D”, 6 Amp Mechanical Relay
Model#98_A-_D _0-0000
Mechanical
Relay
Mechanical Relay
The Electromechanical relay iS an electrical and mechanical d8vice with moving parts.
When power is applied to the relay solenoid, Contact closure is Created through move-
ment of the “Common” Contact of the relay. Off state impedance is 2 O K o h m minimum.
Output 1 Option “E”, 0-I0 VDC
Model# 98_A-_E _0-0000
Process Output,
Proportional value determined by the Control to balance the sensor input and set point.
This value will fall between 0-10VDC depending on your process output type.
Figure 16 -
6 Amp mechanical
Relay, Output 1,
Optlon “D” Wlrlng
Diagram.
Figure 17 -
0-10VDC, Output 1,
Optlon "E" Wiring
Diagram.
Install and Wire, Chapter 2
WATLOW Series 980/985 User’s Manual
17

Figure 18 -
4-2OmA, Output 1,
Option "F" Wiring
Diagram.
Figure 19 -
0-20mA, Output 1,
Option “G” Wiring
Diagram.
Output 1 Option “F", 4-20mA
Model# 98_A-_F _0-0000
Process Output
Proportional value determined by the control to balance the sensor input and set point.
This value will fall between 4-20mA depending on your process output type.
Output 1 Option “G”, O-20mA
Model# 98_A-_G _0-0000
Process Output
Proportional value determined by the control to balance the sensor input and set point.
This value will fall between 0-20mA depending on your process output type.
18
WATLOW Series 980/985 User’sManual
InstallandWire,Chapter 2

Output 1 Option “H”, O-5VDC
Model# 98_A-_H _0-0000
Process Output
Proportional value determined by the control to balance the sensor input and set point.
This value will fall between O-5VDC dependlng on your process output type.
Output 2 Option “B”, Solid State Relay
Model# 98_A-
B 0-0000
--
Solid State Relay
Watlow’s solid state relays change state at zero volts, which is zero-cross switching.”
They are also optically isolated, which means the output circuitry is energized by
infrared light striking a photo-sensitive device. This results in virtual absence of electri -
cally generated noise, plus output to input electrical isolation. Off state impedance is
2 O K o h m s minimum.
Figure 20 -
O-5VDC, Output 1,
Option "H" Wiring
Diagram.
Figure 21 -
S.S. Relay,
Output 2, Option "B"
Wiring Diagram.
InstallandWire, Chapter 2
WATLOW Series 980/985 Users Manual
19

Figure 22 -
DC Output (Open
Collector),
output 2
Option "C" Wiring
Diagram.
Figure 23 -
6 Amp Mechanical
Relay,
Output 2, Option "D"
Wiring Diagram.
Output 2 Option “C", DC Output (Open Collector)
Model# 98_A- C 0-0000
__
-
.
.
.
.
.
.
.
’ 9 - 8 Heat, Cool
+
# or Alarm
Switched DC
Watlow’s solid state switch is a low current DC output (open collector) used to switch an
external power switching device such as a SSR or an electromechanical relay. The input
specifications of the power switching device must match those listed for the SS switch
output. The power switching device must provide isolation between the SS switch
output and load power since the SS switch output is a non-isolated output. Minimum
load resistance is 5 00 ohms. Available current is 9mA minimum and 22mA maximum.
Output 2 Option “D”, 6 Amp Mechanical Relay
Model# 98_A- D 0 - 0000
--
Mechanical
Relay
Mechanical Relay
The electromechanical relay is an electrical and mechanical device with moving parts.
When power is applied to the relay solenoid, contact closure is created through move-
ment of the “common” contact of the relay. Off state impedance is 20K ohms minimum.
20
WATLOW Series 980/985 User’s Manual
InstaIl and Wire, Chapter 2