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Technical Datasheet
TD 00015E/24/EN/01.13
• Two-channel supply for two 2-wire
sensors or transmitters
• Galvanic isolation between all
circuits
• LED status indicators
• Wide range power supply, 20 to
250 V AC/DC, 50/60 Hz
• Top hat (35 mm / 1.38”) DIN rail
mounted housing to EN 50 022-35
Complete product information:
www.e-direct.us/rns221
Specs at a glance:
• HART® signal: Bidirectional
• Diagnostics:
Via HART® status bit or NE43
• Relay output:
Optional for HART® diagnostics
Power supply
RNS221
$ 201.00

2. RNS221 2
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Application / Function
Application The RNS221 power
supply supplies two 2-wire sensors or
galvanically isolated transmitters. This
is only valid for non-hazardous areas.
Using the HART® communication
sockets allows bi-directional
communication to SMART
transmitters (for setup, etc.).
Function The power supply has two
galvanically isolated outputs for
supplying voltage to sensors and
transmitters. A built-in
communication resistance (R = 250 Ω)
enables bi-directional HART®
communication with SMART sensors
and transmitters.The system includes
two channel power supply, 24 V DC,
30 mA, with LED status display for
electrical supply of sensors and
transmitters. All circuits are
galvanically isolated from each other.
The unit is constructed of 35 mm top
hat DIN rail mounting.

3. RNS221 3
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DimensionsTechnical data
Technical data Dimensions (in inches)
Output
Output signal Two channels for transmitter power supply,
open circuit voltage 24 V ±10 %, with
integrated HART® communication resistance
R = 250 Ω for each output
Output current circuit Maximum 30 mA. Short circuit current, both
channels are continuously short circuit
protected
Galvanic isolation Between all circuits
Power supply
Power supply Wide range power supply, 20 to 250 V AC/
DC, 50/60 Hz
Power consumption P ≤ 5 W
Current requirement (Input current limitation) Imax /In < 15
Power failure To EN 61 000-4-11
Operating conditions
Ambient temperature -20 to +60 °C (-4 to +140 °F)
Storage temperature -30 to +70 °C (-22 to +158 °F)
Climatic class To EN 60 654-1 Class B2
Ingress protection NEMA 1
EMC To IEC 61326, transmission Class A,
immunity to IEC 61326 industrial
environment
Over voltage
protection
To EN 61 010-1, Category II, installation
protection fuse ≤ 10 A
0.89 4.41
1 2
CH 2
ENDRESS+HAUSER
RNS 221
CH 1
3.78
4.33
Housing for top hat rail mounting according to IEC 60715
Installation according to instruction manual
Mechanical construction
Weight < 1 lb (approximately 0.140 kg)
Housing PC/ABS, UL 94V0
Terminals Power and signal connections, keyed plug-on
screw terminal, 16 AWG solid wire; 18 AWG
for stranded wire with ferrule.
Communication connection sockets, 2 mm
(0.79”) on front panel of unit
Display and operating level
Display elements 2 yellow illuminated LEDs with connected
outputs; 1 green illuminated LED with main
power connection
Installation hints The installation area must be vibration-free;
keep within the permitted ambient
temperature range; protect the unit from
extreme heat sources
Approvals
CSA approval CSA General Purpose

4. RNS221 4
Application / FunctionOverview Technical data Dimensions
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20 to 250 VAC/DC
50/60 Hz
Connection HART® 2
Connection HART® 1
HART®
X03 X01 X02
L/L+ N/L-
Terminal layout In and outputs
L/L+ L for AC, L+ for DC Input for power
supplyN/L- N for AC, L- for DC
X01 Power supply to transmitter 1 and 2 (+) Output for
transmitter
power supply
X02 Power supply to transmitter 1 and 2 (+)
X03 Power supply to transmitter 1 and 2
with intergrated HART® communication
resistance (R = 250 Ω) (+)
HART® HART® communication to SMART
transmitter
Communication
sockets
(CH 1, CH 2)
Price table
RNS221 Order no. Price/pcs. in USD
Approval Power Supply 1 to 5 6 to 10 11 to 35
Non-hazardous area 20-250 V DC/AC RNS221-A1 228.00 212.00 201.00
Prices valid until 09.30.2013 in U.S. dollars per unit (not including shipping and applicable sales tax).
See Endress+Hauser, Inc. Terms and Conditions of Sale for shipping, tax, and payment terms.
Complete product information:
www.e-direct.us/rns221
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Contact
E-direct
Endress+Hauser, Inc.
2350 Endress Place
Greenwood, IN 46143
Direct order
Internet www.e-direct.us
by phone 888-EH-DIRECT
(343-4732)
per Fax 317-535-8498
E-Mail e-direct@us.endress.com