Yokogawa EJA118 - Manual (Page 11)

IM 1C22H1-01E 2-3
2. HANDLING CAUTIONS
2.8 Insulation Resistance and
Dielectric Strength Test
Since the transmitter has undergone insulation resis-
tance and dielectric strength tests at the factory before
shipment, normally these tests are not required.
However, if required, observe the following precau-
tions in the test procedures.
(a) Do not perform such tests more frequently than is
absolutely necessary. Even test voltages that do not
cause visible damage to the insulation may degrade
the insulation and reduce safety margins.
(b) Never apply a voltage exceeding 500 V DC (100 V
DC with an internal lightning protector) for the
insulation resistance test, nor a voltage exceeding
500 V AC (100 V AC with an internal lightning
protector) for the dielectric strength test.
(c) Before conducting these tests, disconnect all signal
lines from the transmitter terminals. Perform the
tests in the following procedure:
• Insulation Resistance Test
1) Short-circuit the + and – SUPPLY terminals in the
terminal box.
2) Turn OFF the insulation tester. Then connect the
insulation tester plus (+) lead wire to the shorted
SUPPLY terminals and the minus (–) leadwire to
the grounding terminal.
3) Turn ON the insulation tester power and measure
the insulation resistance. The voltage should be
applied short as possible to verify that the insula-
tion resistance is at least 20 M
Ω
.
4) After completing the test and being very careful not
to touch exposed conductors disconnect the
insulation tester and connect a 100 k
Ω
resistor
between the grounding terminal and the short-
circuiting SUPPLY terminals. Leave this resistor
connected at least one second to discharge any
static potential. Do not touch the terminals while it
is discharging.
• Dielectric Strength Test
1) Short-circuit the + and – SUPPLY terminals in the
terminal box.
2) Turn OFF the dielectric strength tester. Then
connect the tester between the shorted SUPPLY
terminals and the grounding terminal. Be sure to
connect the grounding lead of the dielectric strength
tester to the ground terminal.
3) Set the current limit on the dielectric strength tester
to 10 mA, then turn ON the power and gradually
increase the test voltage from ‘0’ to the specified
voltage.
4) When the specified voltage is reached, hold it for
one minute.
5) After completing this test, slowly decrease the
voltage to avoid any voltage surges.
2.9 Installation of Explosion
Protected Type
NOTE
For FOUNDATION Fieldbus explosion protected
type, please refer to IM 1C22T2-01E.
WARNING
To pressure the safety of explosionproof equip-
ment requires great care during mounting,
wiring, and piping. Safety requirements also
place restrictions on maintenance and repair
activities. Please read the following sections very
carefully.
2.9.1 FM Approval
a. FM Intrinsically Safe Type
Caution for FM intrinsically safe type. (Following
contents refer “DOC. No. IFM012-A12 P.1 and 2.”)
Note 1. Model EJA Series pressure transmitters
with optional code /FS1 are applicable for
use in hazardous locations.
• Intrinsically Safe for Class I, Division 1, Groups A,
B, C & D. Class II, Division 1, Groups E, F & G
and Class III, Division 1 Hazardous Locations.
• Nonincendive for Class I, Division 2, Groups A, B,
C & D. Class II, Division 2, Groups E, F & G and
Class III, Division 1 Hazardous Locations.
• Outdoor hazardous locations, NEMA 4X.
• Temperature Class: T4
• Ambient temperature: –40 to 60
°
C
Note 2. Entity Parameters
• Intrinsically Safe Apparatus Parameters
[Groups A, B, C, D, E, F and G]
Vmax = 30 V
Ci = 22.5 nF
Imax = 165 mA Li = 730
µ
H
Pmax = 0.9 W
* Associated Apparatus Parameters
(FM approved barriers)
Voc
≤
30 V Ca > 22.5 nF
Isc
≤
165 mA La > 730
µ
H
Pmax
≤
0.9W