Table of Contents
Advertisement
INSTALLATION CHECKLIST
10.4.5 Switch Inputs
NOTE
10.4.6 Thermistor
and Analog
Inputs
10.4.7 Stop Switch
Input
10.4.8 Contactor
Status
Feedback
10–10
greater than 4000 feet, consult the EIA 485 standard for more details on specific
calculations. Another way to increase the number of units on the data link or the
transmission length is to utilize a RS485 repeater.
•
The shields of the cable should be daisy chained to all of the MM3 Motor Manager 3
serial commons (terminal 27) and grounded at the master only. This provides a
common reference for all of the devices on the data link, as well as, grounding the
data link without creating the potential for ground loops. The potential difference
between the MM3 Motor Manager 3 safety ground (terminals 21 and 48) and the MM3
Motor Manager 3 serial common (terminal 27) should not exceed 36 V.
•
A terminating network consisting of a 120 Ω / 0.25 W resistor in series with a 1 nF /
50 V general purpose mono ceramic or equivalent capacitor must be placed across
the positive and negative terminals at both ends of the data link (terminals 39 and 40
on the MM3 Motor Manager 3). This is to provide the 200 mV separation between the
positive and negative terminals of the device, as well as to eliminate any reflected
signals and ringing.
The MM3 Motor Manager 3 has 16 switch inputs that operate on 120 V AC when the
control voltage switch is set to 120 V AC and 240 V AC when the control voltage switch is
set 240 V AC.
It is recommended that the switch terminals are activated from the same source as is
connected to Terminals 23 and 24. The common of the switch inputs is though terminal
23.
An external source can be used to supply the circuitry into the MM3 Motor Manager 3
switch inputs providing that the external source is in phase with the control voltage of the
MM3 Motor Manager 3. The MM3 Motor Manager 3 switches the inputs on and off
internally, to minimize power consumption, at a frequency determined by the control
voltage. If the external source is not in phase with the control voltage to the MM3 Motor
Manager 3, the timing will be off which could cause errors when reading the switch inputs.
If an external source is used to supply the control signals to the MM3 Motor Manager 3
switch inputs, the source should be fused to protect against fault conditions in the circuitry.
Due to the small voltage levels coming into the MM3 Motor Manager 3 from the thermistor
and external analog device, shielded cable is recommended to minimize any noise that
may be picked up. These wires should be routed away from any power carrying cables.
The STOP switch input on the MM3 Motor Manager 3 must be energized before the MM3
Motor Manager 3 is available to perform a start. If the contactor is being energized and de-
energized externally to the MM3 Motor Manager 3, this terminal will need a jumper from
terminal 24 before the MM3 Motor Manager 3 will seal in contactor A.
The MM3 Motor Manager 3 must see feedback from contactor A and contactor B auxiliary
contacts into the applicable status switch inputs (terminals 15 and 16) within 1 second of
closing the contactor. If this feedback is not received, the MM3 Motor Manager 3 will open
the contactor instead of sealing it in, and will alarm with an open control circuit.
CHAPTER 10: MISCELLANEOUS
MM3 MOTOR MANAGER 3 – INSTRUCTION MANUAL
Advertisement
Table of Contents
