Wiring. YOKOGAWA EJA 440A, EJA 430A, EJA 310A

6. Wiring

6.1 Wiring Precautions

IMPORTANT

• Lay wiring as far as possible from electrical noise sources such as large capacity transformers, motors, and power supplies.

• Remove electrical connection dust cap before wiring.

• All threaded parts must be treated with waterproofing sealant. (A non-hardening silicone group sealant is recommended.)

• To prevent noise pickup, do not pass signal and power cables through the same ducts.

• Explosion-protected instruments must be wired in accordance with specific requirements (and, in certain countries, legal regulations) in order to preserve the effectiveness of their explosion-protected features.

• The terminal box cover is locked by an Allen head bolt (a shrouding bolt) on CENELEC and IECEx flameproof type transmitters.

When the shrouding bolt is driven clockwise by an Allen wrench, it is going in and cover lock is released, and then the cover can be opened by hand. See Subsection 9.4

“Disassembly and Reassembly” for details.

6.2 Selecting the Wiring

Materials

(a) Use stranded leadwires or cables which are the same as or better than 600 V grade PVC insulated wire (JIS C3307) or equivalent.

(b) Use shielded wires in areas that are susceptible to electrical noise.

(c) In areas with higher or lower ambient temperatures, use appropriate wires or cables.

(d) In environment where oils, solvents, corrosive gases or liquids may be present, use wires or cables that are resistant to such substances.

(e) It is recommended that crimp-on solderless terminal lugs (for 4 mm screws) with insulating sleeves be used for leadwire ends.

<6. Wiring>

6-1

6.3 Connections of External

Wiring to Terminal Box

6.3.1 Power Supply Wiring Connection

Connect the power supply wiring to the SUPPLY + and – terminals.

Transmitter terminal box

+

Power supply

–

Figure 6.1 Power Supply Wiring Connection

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6.3.2 External Indicator Connection

Connect wiring for external indicators to the CHECK

+ and – terminals.

(Note) Use a external indicator whose internal resistance is 10Ω or less.

External indicator

Power supply

+

–

Transmitter terminal box

Figure 6.2 External Indicator Connection

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6.3.3 BRAIN TERMINAL BT200

Connection

Connect the BT200 to the SUPPLY + and

– terminals (Use hooks). The communication line requires a reception resistor of 250 to 600Ω in series.

BT200

Transmitter terminal box

+

Power supply

–

Ignore the polarity since the BT200 is

AC-coupled to the terminal box.

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Figure 6.3 BT200 Connection

IM 01C21D01-01E