STT 250 Smart Temperature Transmitter - Honeywell

STT 250 Smart Temperature Transmitter
MEASUREMENT & CONTROL
The STT250 is the latest
addition to the popular STT
3000 family of Smart
Temperature Transmitters. It is
targeted at reduced cost, direct
head mountings on the
temperature sensor and is ideal
for a wide range of applications.
It comes with a variety of
housings and is also suitable for
2’’ pipe, wall or DIN rail
mounting.
It supports temperature
measurements from either
thermocouples (T/C) or
resistance temperature detectors
(RTD) and scales the
measurement into the required
analog output signal.
The output signal can be provided
as a 4-20 mA signal with either
HART ® or Honeywell’s Digitally
Enhanced (DE) protocol, or as a
digital signal for direct digital
integration into Honeywell control
systems.
The range of T/Cs and RTDs
supported cover the most commonly
used sensors and includes 4-wire
RTDs, both 0.00385 and 0.00392
temperature coefficients, 8 T/Cs and
also millivolt and resistance inputs.
All transmitter configuration and
diagnostics checks are performed
from a handheld communicator,
either the Smart Field
Communicator (SFC) or a HART®
communicator, or the Honeywell
PC-based configuration toolkit
(SCT). Configuration can be
performed either at the transmitter
connection terminals or remotely
over the 4-20 mA wiring, even up to
1 mile / 1500 m away.
The hockey puck shaped STT250
module includes a DIN standard 33
mm spring loading facility with the
installation holes through the
module and a central channel for
bringing the sensor leads to the
connection screws.
Unlike many other suppliers’
transmitters, the STT250 has a hard
wire link for selection of Upscale or
Downscale Failsafe in the event of a
sensor or other failure. This ensures
that even with corrupted memory,
the unit will take the appropriate
failsafe action.
The STT250 is available in 3
models:
• Choose the STT25M for the 4-20
mA output version, configurable
locally or remotely from the SFC.
• Choose the STT25H for the
HART® version with 4-20 mA
output, configurable locally or
remotely from a HART®
handheld communicator.
• Choose the STT25D for the digital
DE protocol for direct digital
integration into a distributed control
system.
Integral or remote indicators can also
be supplied with the STT250 as either
analog moving coils or digital liquid
crystal displays.
STT250 benefits
Reduced installation costs
Direct sensor head mounting avoids
the costs of installing and wiring a
separate transmitter housing.
Easy retrofits
With its compact size and wide range
of supported sensors, the STT250 is
the convenient retrofit for any 2-wire
temperature transmitter, whether
conventional 4-20 mA, HART ® or
DE protocol.
Reduced maintenance costs
On-line diagnostics and remote
access ensures efficient use of
maintenance resources.
More secure operation
Instant alarm generation on sensor
fault and post read validation ensure
operational security.
Complete thermal solutions
available from Honeywell
A full range of sensors and
thermowell accessories is available to
enable you to purchase an integrated
transmitter / sensor / thermowell
solution from a high-quality and
competitively priced supplier who
knows both measurement and control.
HART is a registered trademark of the HART Communication Foundation

Condensed Specifications
Performance
Accuracy Pt100 Sensor (α=0.00385) ±0.15°C digital accuracy (Other RTDs supported Pt200 and Pt100 with α=0.00392)
Accuracy Thermocouple Type J ±0.3°C digital accuracy (Other T/Cs supported : Types B, E, K, N, R, S &T.)
Output D/A Accuracy ±0.025% of span Cold Junction Accuracy : ±0.5°C
Total Reference Accuracy
Digital Ambient Temperature Effect
(per 10°C change from 23°C ref.)
Output D/A Ambient Temp. Effect
(per 10°C change from 23°C ref.)
Cold Junction Ambient Temp. Effect
Total Output Ambient Temp. Effect
Operating Conditions
Analogue 4-20mA mode = Digital accuracy + Output D/A accuracy + CJ accuracy (T/Cs only)
Digital DE mode = Digital accuracy + CJ accuracy (T/Cs only)
RTDs or Ohms : 0.050% of reading in Ohms
T/Cs or mV : 0.080% of reading in mV
±0.045% of span
40 : 1 rejection for ambient temperature changes from 23°C reference
Analogue 4-20mA mode = Digital effect + Output D/A effect + CJ effect (T/Cs only)
Digital DE mA mode = Digital effect + CJ effect (T/Cs only)
Reference Condition Rated Condition Operative Limits Transportation
and Storage
Ambient Temperature 23 °C ± 2 -40 to 45 - 40 to 85 - 50 to 100
Humidity : Rack mounted % RH 10 to 55 5 to 95 5 to 100 5 to 100
In field housing % RH 10 to 55 5 to 100 5 to 100 5 to 100
Supply Voltage
Voltage range 10.8 to 35 Vdc at the transmitter terminals
Output
4-20 mA or Honeywell digital DE protocol. HART and DE available with 4-20 mA output
Output Current
Current overrange 3.8 to 20.8 mA. Failsafe limits < 3.8 and 21.8 mA. Alarm levels can be changed with the
handheld communicator to meet the Namur NE43 requirements.
Load Resistance
0 to 1100 Ω
Vibration
Maximum of 4g over 15 to 200 Hz (restricted to 3g with indication meter)
Shock
Maximum of 40g
Input/Output Galvanic Isolation
Withstands 500 Vac dielectric strength test for 1 minute.
Sensor Open Circuit
Open circuit/burnout detection is user selectable. Upscale or downscale with critical status message. Latching or
non-latching sensor burnout action.
EMC Compliance
In compliance with 89/336/EEC, ElectroMagnetic Compatibility (EMC) Directive
RFI Rejection
± 0.1 % of span at 30V/m over 20 to 1,000MHz in metallic housing and with shielded cables
Physical Mounting, Construction and Approvals
Mounting
The STT250 temperature transmitter is designed to be mounted in a DIN Form A (33mm pitch spring loading) housing for direct
installation with the temperature sensor or can be provided in a remote pipe or wall mount housing. The module can be DIN rail
mounted to a top hat or G rail via a clip. Refer to Specification EN01-6032 for details.
Diameter 52mm Height 29.2mm
Net weight
0.075 kg (0.2 lbs)
Safety Approvals
The STT250 temperature transmitter module is Intrinsically Safe to Cenelec, FM and CSA standards when used with a suitable safety barrier. It is Zone 2
and Explosion-Proof to Cenelec, FM and CSA standards when installed in a suitable housing.
Note that the Cenelec EEx d IIC T6 approval requires that the sensor entry to the direct head mount housing is protected by a flametrap. The STT250 should be ordered
complete with housing and sensor to comply with this requirement.
Thermowell & Probe Availability
STT250 can be supplied complete with any of the previously listed thermocouple or RTD sensors and with any of a wide range of thermowells. Refer to Specification
EN01-6033 [outside North America] or 34-44-29-01 [in North America] for details.
The range of thermowells available as a total thermal solution cover almost every possible requirement :
Materials : Carbon Steel, 304SS, 316SS, 316L SS, Hastelloy C-276, Monel 400, Inconel, and many others.
Types : Threaded or flanged, with or without lagging and solid drilled, forged or fabricated construction.
Flange types : Raised Face, Flat Face and Ring Type joint flanges available in 1 to 3 inch sizes or 15 to 200mm.
Flange Ratings : ANSI 150 to 2500, BS 4504 NP6 to NP100, BS 10 Tables D to K and API 6A 5000 to 15000lb.
(other materials, types and accessories available on request).
Distributor :
Industrial Automation and Control
http://europe.iac.honeywell.com
In the U.S.A.: Honeywell Industrial Automation and Control, 16404 North Black Canyon Hwy., Phoenix, AZ 85023, (602) 313-5000
In Europe: Honeywell PACE, 1 Avenue du Bourget, B-1140 Brussels, Belgium, (32) 2-728-211
Honeywell S.A., Zone Industrielle de Longpré, F-80084 Amiens Cédex 2, France, (33-3) 22-54-56-56
In Asia: Honeywell Asia Pacific Inc., N° 19, Toa Payoh, Lorong 8 #06-00, Singapore 1231, 354-6768
In the Mediterranean: Africa & Middle East Region, Honeywell SpA, Via Vittor Pisani 13, 20124 Milano, Italy, (39-2) 67731
In Canada: The Honeywell Centre, 155 Gordon Baker Rd., North York, Ontario M2H 3N7, 1-800-461-0013
In Latin America: Honeywell Inc., 14505 Commerce Way, Suite 500, Miami Lakes, Florida 33016-1556, (305) 3642300
EN3I – 6048 09/99