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© 2014 Chromalox
®
, Inc.
1-888-996-9258
1. Set Current Limit (I LIM) pot to 0% for full current output (CCW).
Current Limit is for limiting current for loads that have
extreme hot to cold resistance ratios or are overrated. We
recommend for these types of loads to adjust I LIM (Cur
-
rent Limit) to 50% or less. This will also decrease voltage
as well as current. 0% Current Limit gives 100% current
output (CCW). 100% Current Limit gives 10% current
output (CW).
2. Set Manual (MAN) pot to zero so unit will not be biased above
input (CCW).
Manual control adjustment provides a means of setting
the output level of the MaxPac Power Pak in the absence
of controlling instrumentation. The manual control signal
value “adds” to the controlling instrument to set mini
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mum output. The desired output power level may be set
by adjusting the manual control. This value of output will
then be present even in the absence of a control signal.
3. Set Remote Manual pot to zero output so unit will not be biased
above input (CCW). (Jumper pins 4 & 5 if not used.)
Remote Manual control adjustment provides a means
of setting the output level of the MaxPac Power Pak in
the absence of controlling instrumentation. The Remote
Manual control is also effective when a control signal
is connected. The Remote Manual control signal value
“adds” to the controlling instrument to set minimum
output. The desired output power level may be set by
adjusting the Remote Manual control. This value of out
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put will then be present even in the absence of a control
signal. Connect Remote Manual pot wire to Pin 4 (CCW),
Pin 5 (W), and Pin 6 (CW) of plug-in connector.
4. Check for open contact for Emergency Shutdown.
Emergency Shutdown inhibits all SCR trigger pulses
regardless of the level of the input signal or manual
potentiometer. For Emergency Shutdown, close contact
Pin 7 to Pin 8 of plug-in connector. Leave contacts open
for operation.
5. Check for polarity of input signal.
6. Adjust input signal to low end of scale.
Zero Adjust control sets the power output starting point
or reference. Thus, it effectively cancels positive inputs
to the MaxPac Power Pak.
EXAMPLE: 0 - 5 mA input à set to 0 mA input
4 - 20 mA input à set to 4 mA input
7. With power off, connect line voltage and load as shown.
8. Connect meter to input and output.
WARNING: Set meter to correct scale to read proper input
or output.
9. Apply power to unit.
10. Adjust input signal to low end of scale.
11. Using the Zero pot, adjust the output voltage just to zero volts.
12. Adjust input signal to top end of scale.
Gain Adjust Control sets the maximum power output for
maximum input signal.
EXAMPLE: 0 - 5 mA input: set to 5 mA input
4 - 20 mA input: set to 20 mA input
13. Using the Gain pot, adjust output voltage just to maximum
volts.
14. Repeat steps 11, 12, 13, and 14 until no adjustment is
necessary of Zero and Gain pots for proper output voltage
indication. Voltage output should increase proportionally to the
signal input applied.
15. Adjust input signal to low end of scale (zero voltage output).
16. With Manual pot at zero for zero voltage output, adjust (CW)
to 100% for full voltage output. Voltage output should
increase proportionally. Return to CCW position and output will
decrease to zero output.
17. With Remote Manual at zero for zero voltage output, adjust
(CW) to 100% for full voltage output. Voltage output should
increase proportionally. Return to CCW position and output will
decrease to zero output.
18. With Manual pot (CW) at 100% and I LIM (Current Limit) at
0%,
adjust I LIM towards 100% noting that voltage
output de
creases with the adjustment of the
Current Limit pot. Adjust
Current Limit pot for your
application, if needed.
19. Turn POWER OFF and remove meters. TEST COMPLETE.
4.2.6 - Calibration (MaxPac IP):
Many high-temperature heating elements exhibit extreme hot to cold resistance ratios. Heating elements composed of Platinum,
Molybdenum, Tungsten, and Tantalum, to name a few, draw excessive current on start-up. Depending on the mass of the elements,
these “high starting currents” may exist for extended periods of time. Generally, once the elements have achieved their normal operat
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ing temperatures, the current drawn through the MaxPac Power Pak will fall within the rating of the unit. For these types of loads, we
recommend adjusting the I LIM (Current Limit) to 50% or less. This will decrease voltage as well as current.