Hoffman Controls 610 Series - Page 19

19
protected with a Model 610 Digital Current Monitor, by looping
one of the motor's power wires, through the 0.925 inch diameter
hole in the CT, three (3) times (depending on the wire's diameter).
In this case, the Model 610 will sense the motor's FLA as 6 amps
(3 wire loops times the 2 amp FLA current).
The current trip value is determined by selecting the
allowed overcurrent percentage and using the following formulas:
To calculate
an 8% over current trip value for the 2 amp motor
above:
O
vercurrent Ratio = (8% + 100%) / 100 = 1.08
Trip Value = 1.08 times 2 amps times 3 wire loops = 6.48 amps.
Use a trip value of 6.5 amps.
1)
The speed at whi
ch the LCD screen's values change is
variable. Holding the
UP
or
DOWN
button down
causes the
displayed value to change slowly at first and th
en speed up notice-
ably. When making large value changes hold the button down
until the displayed number is close to the desired value. Then
release the button, wait 1 second, and press the button down again
to slowly reach the desired value.
2) Figures 10a & 10b
below show a summary of the unique
push button presses, and their results, that are available on the
Digital 610 when the Home Screen is present on the LCD.
Figure 10a
Pressing the
UP
push button, as shown in
Figure 10a
,
causes
the LCD screen to display
the following information about the last
trip that occurred:
1)
The trip type (current, phase imbalance, temp high, temp
low, phase order etc.) or;
2)
The value that caused the trip, and the time in hours since
the last trip occurred (up to 32,000 Hrs.) or;
3)
The stored current values, for all three phases, that caused a
phase imbalance during motor startup.
Figure 10b
Pressing
the
DOWN
button, as shown in
Figure
10
b
,
causes
the
LCD screen to display, in real time, all three phase currents in
amps, and both sensor
temperatures in
°
F (or Ohms)
, even when
the
y are not being used (installed) or have not been selected
. The
unused phase currents and temperature sensor values are displayed
as "
0
".
selection.
The
default is "
even parity
."
4
2
.
The display should indicate “
Reset Control to Factory
Sets?
” The default is “
No
.” Press the
ENTER
button.
ENTER button. ENTER
IMPORTANT:
If you select “
Yes
” and press the
ENTER
b
utton, all the Model 610 Digital Current Monitor's parameters
are reset to the following factory default settings shown below:
• 3 Phase monitoring.
• Trip Level = 10.0 amp.
• Exhaust and Oil temperature sensors are not used.
• Lockout occurs when the 3
rd
trip occurs.
• Auto reset delay = 5 minutes.
• Modbus slave address = 1.
•
Modbus baud rate = 19200.
• Modbus parity = even.
This completes the setup of all control parameters.
Reconnec
t
any previously removed wires
, apply 24 VAC power
to the Model 610 Digital Current Monitor(s) and
line power to
the motor contactor(s). Observe the LCD screen and the motor's
operation:
• Verify the current displayed
on the Model 610's LCD screen
matches the motor's nominal FLA current.
• If the exhaus
t and / or oil temperature sensors are used in
this application
, verify the temperatures displayed on the LCD
screen, while pressing the
DOWN
button, match the measured
exhaust / oil temperatures recorded by the installer (using an
appropriate temperature sensing device).
•
If the system works correctly, no operational updates are
needed.
•
If the system does not work correctly, determine the specific
cause for the anomaly and fix it. When the anomaly's solution
involves an update to the Model 610 Digital Current Monitor's
parameters, follow the
Sequence of Operation
section instruc-
tions (pages 16 thru 19) to update the specific parameter(s) needed
to achieve the best possible system operation. After any update(s)
or repairs have been made, observe the entire system's operation
again, to verify the update(s) or repairs worked.
For motors drawing less than 5 amps, each motor's power wire
can be looped through its associated CT(s) a number of times
(depending on wire diameter to increase the sensed current. When
using more than one (1) CT, loop power wires through each CT
the same number of times.
Important:
Adjust the current trip value accordingly.
For example:
A single phase motor with an FLA of 2.0 amps, can be
Sequence of Operation (con't)
Motor & Operating Tips
Motor
Tip
Motor TipMotor
Operating
Tip
Operating TipOperating
Final Checkout Procedure
Overcurrent Ratio = (
overcurrent percentage + 100%
)
divided by 100
.
Trip Value =
Overcurrent Ra
tio
times
motor's FLA
times
3 (wire loops)
.

