RH2B-ULAC110-120V IDEC Corporation, RH2B-ULAC110-120V Datasheet - Page 11

• Manufacturer Part Number: RH2B-ULAC110-120V
• Description: Relay; E-Mech; Gen Purp; DPDT; Cur-Rtg 10A; Ctrl-V 110/120AC; Vol-Rtg 240/30AC/DC
• Manufacturer: IDEC Corporation

Specifications of RH2B-ULAC110-120V

• Brand/series: RH Series
• Contact Form: DPDT
• Current, Rating: 10 A
• Dimensions: 0.819 in. L x 1.07 in. W x 1.39 in. H
• Function: General Purpose
• Material, Contact: Silver Cadmium Oxide
• Relay Type: Electro Mechanical
• Resistance, Coil: 4170 Ohms
• Resistance, Contact: 50 milliohms (Max.)
• Standards: UL, CSA, CE, TUV
• Temperature, Operating, Maximum: 70 °C
• Termination: Plug-In Blade
• Voltage, Control: 115 VAC
• Voltage, Rating: 240 VAC
• Lead Free Status / Rohs Status: RoHS Compliant part

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Driving Circuit for Relays
1. To ensure correct relay operation, apply rated voltage to the relay coil.
2. Input voltage for the DC coil:
3. Leakage current while relay is off:
4. Surge suppression for transistor driving circuits:
A complete DC voltage is best for the coil power to make sure of stable relay
operation. When using a power supply containing a ripple voltage, suppress
the ripple factor within 5%. When power is supplied through a rectifi cation
circuit, the relay operating characteristics, such as pickup voltage and dropout
voltage, depend on the ripple factor. Connect a smoothing capacitor for better
operating characteristics as shown below.
When driving an element at the same time as the relay operation, special
consideration is needed for the circuit design. As shown in the incorrect
circuit below, leakage current (Io) fl ows through the relay coil while the relay
is off. Leakage current causes coil release failure or adversely affects the
vibration resistance and shock resistance. Design a circuit as shown in the
correct example.
Incorrect
When the relay coil is turned off, a high-voltage pulse is generated, causing a
transistor to deteriorate and sometimes to break. Be sure to connect a diode
to suppress the back electromotive force. Then, the coil release time becomes
slightly longer. To shorten the coil release time, connect a Zener diode
between the collector and emitter of the transistor. Select a Zener diode with
a Zener voltage slightly higher than the power voltage.
R
Io
Smoothing
Capacitor
Operating Instructions
+
–
TE
R
Relay
Back emf
suppressing diode
Correct
Ripple Factor (%)
Emax
Emin
Emean
+
–
R
Emin Emax Emean
Relay
= Maximum of pulsating current
= Minimum of pulsating current
=
DC
R
mean value
Emax – Emin
Emean
Operating Instructions
Pulsation
× 100%
DC
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Protection for Relay Contacts
1. The contact ratings show maximum values. Make sure that these values are
2. Contact protection circuit:
3. Do not use a contact protection circuit as shown below:
Soldering
1. When soldering the relay terminals, use a soldering iron of 30 to 60W, and
2. Use a non-corrosive rosin fl ux.
not exceeded. When an inrush current fl ows through the load, the contact
may become welded. If this is the case, connect a contact protection circuit,
such as a current limiting resistor.
When switching an inductive load, arcing causes carbides to form on the
contacts, resulting in increased contact resistance. In consideration of contact
reliability, contact life, and noise suppression, use of a surge absorbing circuit
is recommended. Note that the release time of the load becomes slightly
longer. Check the operation using the actual load. Incorrect use of a contact
protection circuit will adversely affect switching characteristics. Four typical
examples of contact protection circuits are shown in the following table:
Generally, switching a DC inductive load is more diffi cult than switching a DC
resistive load. Using an appropriate arc suppressor, however, will improve the
switching characteristics of a DC inductive load.
quickly complete soldering (within approximately 3 seconds).
Power
Power
C
Power
Power
Power
Power
C
+
–
Load
Load
C
C
R
D
R
This protection circuit is very effective in arc suppression when
opening the contacts. But, the capacitor is charged while the
contacts are opened. When the contacts are closed, the capacitor
is discharged through the contacts, increasing the possibility of
contact welding.
This protection circuit is very effective in arc suppression when
opening the contacts. But, when the contacts are closed, a current
fl ows to charge the capacitor, causing contact welding.
Ind. Load
Ind. Load
Ind. Load
Ind. Load
This protection circuit can be used when the load
impedance is smaller than the RC impedance in an
AC load power circuit.
•
•
This protection circuit can be used for both AC and
DC load power circuits.
R: Resistor of approximately the same resistance
value as the load
C: 0.1 to 1 μF
This protection circuit can be used for DC load power
circuits. Use a diode with the following ratings.
Reverse withstand voltage: Power voltage of the
load circuit x 10
Forward current: More than the load current
This protection circuit can be used for both AC and
DC load power circuits.
For a best result, when using a power voltage of 24
to 48V AC/DC, connect a varistor across the load.
When using a power voltage of 100 to 240V AC/DC,
connect a varistor across the contacts.
R: Resistor of approximately the same resistance
value as the load
C:0.1 to 1 μF
Relays & Sockets