9

EB3C Relay Barrier

Precautions for Operation

1. Installation of EB3C Relay Barriers

(1) The EB3C can be installed in any direction.

(2) Install the EB3C relay barrier in a safe area (non-hazardous

area) in accordance with intrinsic safety ratings and param-

eters. To avoid mechanical shocks, install the EB3C in an

enclosure which suppresses shocks.

(3) When installing or wiring the EB3C, prevent electromag-

netic and electrostatic inductions in the intrinsically safe cir-

cuit. Also prevent the intrinsically safe circuits from

contacting with another intrinsically safe circuit and any

other circuits.

Maintain at least 50 mm clearance, or provide a metallic

separating board between the intrinsically safe circuit and

non-intrinsically safety circuit. When providing a metallic

separating board, make sure that the board fits closely to

the enclosure (top, bottom, and both sides). Allowable

clearance between the enclosure and board is 1.5 mm at

the maximum.

The clearance of 50 mm between the intrinsically safe cir-

cuit and non-intrinsically safe circuit may not be sufficient

when a motor circuit or high-voltage circuit is installed

nearby. In this case, provide a wider clearance between the

circuits referring to 5 (3) “Minimum Parallel Distance

between the Intrinsically Safe Circuit and Other Circuits.”

(4) In order to prevent contact between intrinsically safe circuits

and non-intrinsically safe circuits, mount EB3C units with

terminals arranged in the same direction.

(5) Maintain at least 6 mm (or 3 mm according to IEC60079-

11: 1999) clearance between the terminal of intrinsically

safe circuit and the grounded metal part of a metal enclo-

sure, and between the relay terminal block of an intrinsically

safe circuit and the grounded metal part of a metal enclo-

sure.

(6) For installing the EB3C, mount on a 35-mm-wide DIN rail or

directly on a panel using screws. Make sure to install

securely to withstand vibration. When mounting on a DIN

rail, push in the clamp completely. Use the BNL5 or BNL6

mounting clips on both sides of the EB3C to prevent from

moving sideways.

(7) Excessive extraneous noise may cause malfunction and

damage to the EB3C. When extraneous noise activates the

voltage limiting circuit (thyristor), remove the noise source

and restore the power.

2. Terminal Wiring

(1) Using a ø5.5 mm or smaller screw driver, tighten the termi-

nal screws (including unused terminal screws) to a torque

of 0.6 to 1.0 N·m (recommended value).

(2) Make sure that IP20 is achieved when wiring. Use insula-

tion tubes on bare crimping terminals.

(3) To prevent disengaged wires from contacting with other

intrinsically safe circuits, bind together the wires of one

intrinsically circuit.

(4) When the adjacent terminal is connected to another intrinsi-

cally safe circuit, provide an insulation distance of at least 6

mm.

3. Switches in the Hazardous Area

(For Japan application only)

(1) A switch contains the switch contact, enclosure, and inter-

nal wiring. A switch contact refers to an ordinary switching

device which consists of contacts only, such as a pushbut-

ton switch. See below.

Applicable Switches

Note: For installation in hazardous areas and connection to the EB3C, use

switches which are certified, approved, or considered to be simple

apparatus in relevant standards in each country.

(2) When the switch has internal wiring or lead wire, make sure

that the values of internal inductance (Li) and capacitance

(Ci) are within the certified values.

(3) Enclose the switch contact’s bare live part in an enclosure

of IP20 or higher protection.

(4) Depending

on

the

explosion-protection

specifications

according to TIIS Japan, the exposed area of plastic switch

operator is limited as follows:

(5) Attach the certification mark supplied with the EB3C on the

EB9Z-A or EB9Z-A1 switch (for Japan application).

(6) Magnesium content of metallic enclosure must be 6% or

less (steel and aluminum are acceptable).

(7) When the switch operator of plastic enclosure has a wider

exposed area than the following limits, attach a caution

label as shown below.

(8) For the 1-circuit separate wiring, a resistor to prevent reed

switch contact welding and an LED miniature pilot lights

can be connected in series with the contact. See below.

Use the terminal screw of M3 or larger.

Applicable Resistor Ratings

• Applicable LED Type

IDEC’s IPL1 series LED miniature pilot lights.

Intrinsically Safe Circuit

Intrinsically Safe Circuit

Non-intrinsically

Safe Circuit

EB3C

EB3C

EB3C

EB3C

EB3C

Control

Switches

Push-pull Switches

Pushbutton, Foot, Trigger, Rocker, Grip

Twisting Switches

Rotary, Selector, Cam, Drum, Thumb

wheel

Lever and Slide

Switches

Toggle, Multidirectional, Wobble stick,

Lever, Slide switch

Sensing

Switches

Displacement

Switches

Microswitch, Limit, Magnetic proximity,

Door, Reed, Mercury

Level Switches

Liquid level

Others

Pressure, Temperature

Resistance

100

Ω maximum

Rated Wattage

0.5 to 3W

Type

Metal (oxide) film resistors

To prevent electrostatic

charges, do not rub the switch

surface during operation.

Use a soft cloth dipped with

water for cleaning.

Caution

Caution Label Example

R

Reed Switch

EB3C

EB3C-3L catalog Page 9 Monday, February 13, 2006 1:44 PM