Liquid Controls SP2850 (MS-649) - Manual (Page 7)

Sponsler, Inc. Model SP2850-TC with MS649 Page 7 DOC#: MN-2850
WIRING
AC/DC Connections:
NOTE: Connect power only after other connections are finished. Do not touch the live AC power terminals. The
unit has been designed with an isolated AC input, therefore polarity is not a concern for the AC power. The chassis
is plastic, therefore earth ground is not used. For DC operation, connect +DC to terminal 14 and -DC to terminal 12.
Although the unit is designed to be immune from line or RF interference, the unit is controlled by a microprocessor
and an electrically ‘noisy’ environment could cause operating problems. The input power lines should not be
common to power lines or motors, pumps, contactors, etc.
Four sources of noise can occur:
1) AC power line noise- If the unit cannot be connected to an electrically clean power source, an inductive load
suppressing device (MOV as GE#V130LA1 or Resistor, Capacitor as Paktron # .2uf/220 ohm @400V) can be
installed. Although locating the suppressor across the AC supply at the unit should help, best results are obtained
by connecting the suppressor across the leads of the ‘load’ at the device causing the spikes.
2) Input line noise- The noise is carried on the input and DC ground lines. Make sure the input wires are not run
into the unit in a bundle with power input lines. We recommend using shielded cable. Connect the shield to DC
ground of the unit and ‘earth’ at one point in the circuit preferably at the DC ground terminal of the unit.
3) Output lines- The unit has two open collector outputs and two relay outputs. When these outputs are used to
run external relays or solenoids, spikes can be generated upon activation. This noise can spread through the
instrument causing operating problems. If the source is a DC operated device, a general purpose diode (IN4004)
placed across the solenoid prevents electrical noise spikes. Connect the cathode (banded side) to the more
positive side of the coil. If the source is an AC operated device, use a Resistor, Capacitor or MOV across the coil.
4) DC output supply- Noise can be generated on the DC output supply if it is used to drive inductive loads or if the
current draw exceeds 100mA. Insure that all inductive loads have a diode (such as IN4004) across the coil and that
the current does not exceed 100mA.
WIRING CONNECTIONS
Terminal Connections:
1 - REMOTE START
2 - SCALED OUTPUT (OPEN COLLECTOR)
3 - ANALOG OUTPUT
4 - INPUT A (PULSE)
5 - RESET INPUT
6 - REMOTE STOP
7 - RTD EXCITATION +
8 - RTD SENSE + (OPT SECURITY OUT)
9 - RTD SENSE - / VOLTAGE INPUT +
10- RTD EXCITATION - / CURRENT INPUT +
11- GROUND (-DC)
12- GROUND (-DC)
13- 12 VOLTS OUT
14- DC POWER IN
15- ISOLATED -12 VOLTS OUT
16- ISOLATED +12 VOLTS OUT
17- AC INPUT
18- AC INPUT
19- PREWARN TRANSISTOR
20- PRESET TRANSISTOR
1 - N.O.
2 - N.C.
3 - COMMON
4 - N.O.
5 - N.C.
6 – COMMON
PRESET
PREWARN