GENERAL DESCRIPTION
The EWPC 902/S is a new series of micro-
processor based and fully programmable
process controllers for single setpoint ap-
plications.
The front keypad of these controllers offers
several alpha-numeric menu prompts to
configure the controller for each specific
application.
Furthermore, the instrument is equipped
with a RS-485 port for the purpose of con-
necting it into a Televis system; is compat-
ible with Televis software rel 2.4 or greater.
In case its use with different software re-
leases is required contact your supplier or
Eliwell Customers’ Service.
Three different versions of this controller
are available: EWPC 902/T/S for
Temperature, EWPC 902/R/S for Relative
humidity and EWPC 902/P/S for Pressure
control.
The EWPC 902/S is supplied in the popu-
lar “32x74” ELIWELL housing.
FRONT KEYPAD
SET
: push to display the setpoint value.
The setpoint can be changed within 5 sec-
onds with the “UP” or “DOWN” button.
The control will automatically switch back
to normal operating mode within 5 sec-
onds; the last entered setpoint will stay in
memory.
UP
: used to increase the setpoint value, as
well as the parameter when in program-
ming. When held down for a few seconds,
the change rate accelerates.
DOWN
: used to decrease the setpoint val-
ue, as well as the parameter when in pro-
gramming. When held down for a few
seconds, the change rate accelerates.
Led “SET”
: on during setpoint
display/change or blinking during program-
ming.
Led “OUT”
: status light of the output.
PARAMETER PROGRAMMING
Programming is easily accessed by holding
the “SET” button down for more than 7
seconds; the first parameter is displayed
while the status light Led “SET” remains
blinking during the programming period.
Other parameters are accessed with the
“UP” and “DOWN” button. With the “SET”
button, the actual setting of each parame-
ter is displayed. To change a parameter
setting, push the “SET” plus the “UP” (or
“DOWN”). The system will automatically re-
turn to its normal operating mode a few
seconds after the programming procedure
is completed or interrupted.
DESCRIPTION OF PARAMETERS
diF
: diFferential.
The switching differential (hysteresis) can
be set with positive value (make on rise) or
with negative value (make on fall).
LSE
: Lower SEt.
This is the lower limit below which the user
cannot change the setpoint; normally set at
the lowest value recommended for the
sensor.
HSE
: Higher SEt.
Similar to “LSE”, however setting an upper
limit for the setpoint.
Att
: Alarm temperature type (“HAL” and
“LAL”).
Ab = absolute;
re = relative.
HAL
: Higher ALarm.
Maximum temperature alarm. Maximum
temperature value – when exceeded the
information is sent to the Televis system.
LAL
: Lower ALarm.
Minimum temperature alarm. When the
temperature reaches a lower value the in-
formation is sent to the Televis system.
Set to a negative value when parameter
“Att = re”.
AFd
: Alarm (Fan) differential.
PAO
: Power-on Alarm Override.
HOW IT IS MADE
• Dimensions: front 74x32 mm
(2.913x1.260"), depth 67 mm
(2.637")
• Mounting: flush panel mount with
mounting bracket
• Protection: the instrument front-
panel is waterproof IP65; an op-
tional snap-on cover can be
supplied to provide additional pro-
tection of the rear terminal block
• Connections: screw terminal block
(2.5 mm
2
; one wire each terminal
only, in compliance with VDE
norms)
• Output: one (1) SPDT relay 8(3)A
250V
A
• Auxiliary output: 12 V
C
/60 mA (for
transducer power supply, e.g. hu-
midity sensor, pressure transducer,
etc.)
• Inputs (depending on model):
PTC / Pt100 / current (4…20 mA;
Ri = 41
Ω
) for EWPC 902/T/S;
EWHS 28/31 for EWPC 902/R/S
and EWPA 007/030 for EWPC
902/P/S
• Serial connection: RS-485 serial
port for connection to the Televis
system
• Televis system compatibility: soft-
ware release 2.3.2 or greater
• 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: 12…24 V
A
/
C
WHAT IT IS
The EWPC 902/S is a series of mi-
croprocessor based and fully pro-
grammable process controllers for
single setpoint applications.
The instrument is equipped with a
RS-485 port for the purpose of con-
necting it into a Televis system.
Three different versions of this con-
troller are available: EWPC 902/T/S
for Temperature, EWPC 902/R/S for
Relative humidity and EWPC
902/P/S for Pressure control.
EWPC 902/S
temperature controller with Televis output
