Rice Lake Survivor RT, Руководство пользователя и инструкция по установке

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Junction Box and Grounding 7
Therefore, the best grounding system for the scale is
the same grounding system used for the incoming AC
power system. The 120 VAC power source used to
power the indicator will be connected to an existing
earth grounded rod system at the scale house or other
building where the indicator is located. This should
consist of a double ground rod system of two 5/8" x 8'
copper rods driven 8' deep at the service entrance
where the local utility company brings their lines into
the building.
The local utility company can test the resistance of the
existing ground rods with a clamp-on megohmeter
that measures zero resistance. A reading of 3¾ or less
is acceptable as a ground. If the test determines that
the grounding system is inadequate, the utility
company can suggest methods to improve the system.
It’s crucial that the scale owner authorize and make
t he r ec om me nd ed i m pro ve me nt s t o ass ur e an
adequate electrical ground. Do not connect the scale
to the AC power supply until the grounding system is
adequate.
Be certain each load cell grounding strap is securely
connected to the top plate and bottom plate of each
load cell mount. There should be metal-to-metal
contact with no presence of paint or grout. This strap
is designed to channel power surges on the deck
around—rather than through—the load cell to ground.
Grounding
Strap
Figure 3-1. Grounding strap on load cell mount.
These, and all, ground connections must be torqued to
a specified value and retorqued at regular service
intervals. A thick coating of anti-oxidant grease
should be maintained on all ground connections to
prevent corrosion.
A separate grounding system conductor must extend
uninterrupted from the main service panel ground to
the scale to protect load cells and scale wiring from
lightning and other transient damage. This ground
wire conductor must be an unsheathed #10 copper
wire or larger. Run the bare ground wire conductor
intact from the AC power ground rod to the scale in a
separate trench.
Bring the wire up from the trench
near the junction box and attach it to the ground lug of
the junction box. A #10 bare ground wire is run from
the ground lug of the junction box to one of the
junction box mounting studs on the scale frame, thus
grounding the scale frame to the same single-point
ground as the AC power for the indicator
.
ground before indicator
To DC Protection Ground
Connection before Indicator
10 ga. Bare Ground Wire
Ground Lug
R41
JP17
JP7
R52
R50
R40
R24
R14
R15
JP20
JP10
R26
R51
R49
R47
JP16
R45
R43
JP9
R23
R21
JP6
JP8
R17
R38
R36
R34
JP11
R32
R30
R28
R10
R8
JP1
R4
R2
R33
JP12
JP2
VR9
JP19 R48
VR7
JP18
R42
R44
R22
R25
R16
R18
VR2
R19
R39
VR10
R35
R37
VR11
R27
R29
R31
R9
R11
R12
R1
R3
R5
VR5
R6
JP5
JMP/NEG JMP/POS
VR8
VR3
VR1
VR12
VR6
J1
VR4
J2
R13
R7
EXPANSION/J9
J5
ARC
R46
JP4
JP3
ARGND
JP14
JP15
JP13
L3
L4
L2
J8
J4
J3
J6
L1 R20
J7
INDICATOR/J10
JP
TRIM
TRIM
TO
-EX
+EX
+SI
-EX
+EX
+SI
-EX
+EX
1
+SI
-EX
+EX
+SI
JP
JP
TO
SIGNAL
2005
SIGNAL
CUT
TO
DISABLE
CUT
CELL#
CELL#
CELL#
SHD
1
SHD
-SI
1
-SI
SHD
-SI
1
-SI
SHD
SIGNAL
CUT
TO
CUT
SECT# DISABLE
CELL#
CELL#
SIGNAL
SIGNAL
SIGNAL
D
L D
DISABLE
CELL#
SECT# DISABLE
CELL#
RICE LAKE WEIGHING SYSTEM
S
JP
-EX
+EX
+SI
-EX
+EX
+SI
-EX
+EX
+SI
-EX
+EX
+SI
SIGNAL
TRIM
TRIM
TRIM
TRIM
TRIM
TRIM
Assembly
-EX
-EX
+EX
+SI
SHD
1
SHD
-SI
1
-SI
1
-SI
SHD
1
-SI
SHD
CONNECT BOTH SHUNTS
TO APPLY SIGNAL
SECT#
SIGNAL
SIGNA
L
SIGNAL
CELL#
PN Rev.
+SI
-SI
-SI
SECT#
+SEN
SHD
+SEN
SHD
DISCONNECT BOTH SHUNTS
TO REMOVE SIGNAL
+EX
-SEN
-SEN
CUT TRACE TO ISOLATE SENSE LINE
Transient Board Connectors
Grounding Lug
Figure 3-2. Junction box ground wire connections.