Eliwell EWTR 910, EWPR 910, EWHR 910 User Manual

GENERAL DESCRIPTION

The EWTR 910 is a new series of micro­processor based and fully programmable
process controllers for single setpoint ap­plications; the output provides ON-OFF or
PID control.
Three different versions of this controller
are available: EWTR 910 for Temperature,
EWHR 910 for Relative humidity and
EWPR 910 for Pressure control.
The instrument is supplied in the standard
EW 72x72 housing.

FRONT KEYPAD

SET: with this button the setpoint value
can be displayed. To change the value, this
button should be activated together with
the “UP” or “DOWN” button. In case para­meter “dro” is set at “S”, the setpoint value
(SV) can be changed with the “UP” or
“DOWN” button only, while the process
temperature (PV) can be displayed with the
“SET” button.
UP: used to increase the setpoint value, as
well as the parameter when in program­ming. When held down for a few seconds,
the change rate accelerates.
DOWN: same functions except to de­crease a value.
PRG: programming access button. To ac­cess programming, this button must be
pushed together with the concealed but­ton located under “PRG” and “SET”, all at
the same time.

Led “OUTPUT”: status light of the output.
Led “SV” (Set Value): to indicate that the

Set Value (SV) is displayed. This occurs
when “SET” is pushed (parameter “dro”
set at “P”); it will stay on steady if parame­ter “dro” is set at “S”.

PARAMETER PROGRAMMING

Access the programming by pushing
“PRG”, then the concealed button below
“PRG” and “SET”, all at the same time.
The first parameter will appear and the
“OUTPUT” status light will blink throughout
the programming. Select the desired para­meter with the “UP” and “DOWN” button.
With the “SET” button, the actual setting of
each parameter is displayed. To change a
parameter setting, push the “SET” plus the
“UP” (or “DOWN”).
To exit the programming, push “PRG” plus
the concealed button.

DESCRIPTION OF PARAMETERS

Any parameter which does not apply to a
particular instrument version is automati­cally removed from the programming
menu.
E.g.: a control for Thermocouple input will
not offer parameters “Lci” and “Hci”.
d1: differential setpoint 1.
The switching differential (hysteresis) can
be set with positive value (make on rise) or
with negative value (make on fall). See pa­rameter “HC1”.
LS1: Lower Set 1.
This is the lower limit below which the user
cannot change the setpoint; normally set
at the lowest value recommended for the
sensor.
HS1: Higher Set 1.
Similar to “LS1”, however setting an upper
limit for the setpoint.
Pb: Proportional band.
Only for models with PID option. This val­ue, expressed in degrees, determines the
band-width around the setpoint within
which the instrument provides proportion-

HOW IT IS MADE

• Dimensions: front 72x72 mm
(2.84x2.84"), depth 102 mm (4.00")

• Mounting: flush panel mount with
mounting bracket. Panel cut-out
67x67 mm (2.64x2.64")

• Connections: quick-disconnect
screw terminal blocks (2.5 mm

2

;

one wire each terminal only)

• Display: 12.5 mm LED (0.50")

• Output: one (1) SPDT relays 8(3)A
250V AC, or one (1) “static”
(switched) output 0/12 Vdc 40 mA

• Programmable analog output (op­tional): 4…20 mA or 0…5 V, de­pending on model

• Auxiliary output: 12 Vdc/60 mA
(for transducer power supply, e.g.
temperature sensor, etc.; ground
goes to terminal 10)

• Inputs (depending on model):
PTC / RTD (Ni100, Pt100) /

TC (J, K) / 4…20 mA (Ri = 41 Ω) for

EWTR 910, EWHS 28/31 for
EWHR 910 and EWPA 007/030 for
EWPR 910

• Resolution: 1 °C (°F) or 0,1 °C (°F).
The right-most digit can also be
set to read-out in 0 or 5 only, or in
all 10 digits

• Accuracy: better than 0.5% of full
scale

• Power supply (depending on mod­el): 220, 110, 24 Vac, 50/60 Hz; 12
Vac/dc

WHAT IT IS

The EWTR 910 is a new series of
micro-processor based and fully
programmable process controllers
for single setpoint applications; the
output provides ON-OFF or PID
control. Three different versions of
this controller are available: EWTR
910 for Temperature, EWHR 910 for
Relative humidity and EWPR 910 for
Pressure control.

EWTR/HR/PR 910

rel. 12/96 ing

controllers one output 72x72

2EWTR/HR/PR 910 12/96 ing

al control. See also “PROPORTIONAL
CONTROL”.
It: Integral time, expressed in seconds.
Only for models with PID option. The high­er this setting, the “smoother” the integral
action. A setting of “0” completely elimi­nates the integral function and changes
the controller from PID to PD (output 1).
See also “PROPORTIONAL CONTROL”.
dt: derivative time, also expressed in sec­onds.
Only for models with PID option. The effect
of the derivative action is in direct propor­tion to this time setting. See also “PRO­PORTIONAL CONTROL”.
Sr: Sampling rate, in seconds.
Only for models with PID option. Time be­tween two successive read-outs, for the
computation of the derivative. A low set­ting increases the response time, but also
the sensitivity to noise. Recommended
setting is from 1 to 3.
rSt: manual reSet.
Only for models with PID option. This al­lows the proportional band to be moved
up or down. This parameter is expressed
in degrees and must be set at a value op­posite and corresponding to the noticed
error.
Ar: Anti-reset wind-up band.

Only for models with PID option. This is the
half-band (on either side of the setpoint) in
which the integral action takes place. The
higher this setting, the stronger the integral
action. Recommended initial setting: half
of the value of parameter “Pb”.
Ct: Cycle time (in seconds).
Only for models with PID option. This is the
total time of one ON+OFF cycle of the re­lay during the proportional action. See
“PROPORTIONAL CONTROL”.
od: output delay.
This provides a delay selection for the out­puts in applications where noise may
cause brief erroneous signals from the
sensor to the controller. Factory set at “0”.
Lci: Lower current input.
Read-out corresponding to the “low end
scale” input signal of 4 mA; only for mod­els with current input.
Hci: Higher current input.
Read-out corresponding to the “high end
scale” of 20 mA; only for models with cur­rent input.
LAO: Low Analog Output.
Low end of scale setting of analog output
(only for models with this option; see para­meter “AOF”).
HAO: High Analog Output.
High end of scale setting of analog output

(only for models with this option; see para­meter “AOF”).
CAL: CALibration.
This offers an adjustment up or down of
the read-out, if needed.
Factory set at “0”.
PSE: Probe SElection.
Input type (for RTD or Thermocouples
only).
RTD models: Ni = Ni100; Pt = Pt100.
T/C models: FE = TcJ; Cr = TcK.
AOF: Analog Output Function.
Analog output function (only for models
with this option; see parameters “LAO”
and “HAO”).
ro (read-out) = proportional to the system
temperature, within the read-out values
specified by parameters “LAO” and
“HAO”.
Er (Error) = proportional to temperature de­viation from Setpoint, within the values
specified by parameters “LAO” and
“HAO”.
HC1: Heating / Cooling output 1.
Relay switch function output 1.
H = Heating (humidification; reverse ac­tion);
C = Cooling (dehumidification; direct ac­tion).
rP1: relay Protection 1.
Determines the status of the relay in case
of sensor defect. Factory set at “ro”.
ro = relay open; rc = relay closed
LF1: Led Function 1.
Determines whether the status light is ON
or OFF in relation to output 1.
di = direct = light ON when output 1 is en­ergized;
in = reverse = light OFF when output 1 is
energized.
dP: decimal Point.
Choose whether the resolution is required
with or without decimal point.
oF = without decimal point;
on = with decimal point.
NOTES: (a) the decimal point of models
with current or voltage input is shifted: the
actual value of parameters “Lci” and “Hci”
must be multiplied by 10; (b) on all ver­sions, if a unit is changed from without
decimal point to with decimal point, all pa­rameter values expressed in degrees will
automatically be divided by 10, including
the setpoint !! (c) the decimal point selec­tion is not available on models for thermo­couple input.
dro: display read-out.
Display read-out reversal.
P (Process value) = system temperature
display.
S (Setpoint value) = setpoint temp. display.
AOS: Analog Output Security (only for
models with this optional analog output).
Sensor protection analog output.
Ao (Analog output on) = analog output ON
(100%) in case of sensor defect;
AF (Analog output oFf) = analog output
OFF (0%) in case of sensor defect.
hdd: half digit display.
The right-most digit can be set to read-out

DEFAULT SETTINGS - STANDARD MODELS

Parameter

d1
LS1
HS1
Pb*
It*
dt*
Sr*
rSt*
Ar*
Ct*
od
Lci
Hci
LAO**
HAO**
CAL
PSE
AOF**
HC1
rP1
LF1
dP
dro
AOS**
hdd
tAb

* Parameters visible only for special models with proportional operation (PID).
** Parameters visible only for special models with analog output.

Description

differential set 1
Lower Set limit 1
Higher Set limit 1

Proportional band

Integral time

derivative time

Sampling rate

manual reSet

Anti reset

Cycle time

output delay
Low current input
High current input

Low Analog Output
High Analog Output

CALibration

Probe SElection

Analog Output Function

Heating / Cooling out 1

relay Protection 1

Led Function 1

decimal Point

display read-out

Analog Output Security

half digit display

tAble of parameters

Range

min / max
min / max
min / max

0.1 (1) / max
0 / 999
0 / 999

1 / 10

min / max

0 / max
1 / 500

min / max
min / max
min / max
min / max
min / max
min / max

Ni / Pt / Fe / Cr

ro / Er

H / C

ro / rc

di / in

on / oF

S / P

Ao / AF

n / y

/

Unit

various
various
various

various
seconds
seconds
seconds

various

various
seconds
seconds

various

various

various

various

various

/
flag
flag
flag
flag
flag
flag
flag
flag

/

Default

1 (C) / –1 (H)

min
max
100
500

30

1
0

100

30

0

min
max

min
max

0

/

ro

/
ro
di

oF

P

AF

n

/