AERCO SmartPlate - Manual (Page 7)

SmartPlate Installation, Operation & Maintenance Manual
CHAPTER 1 – GENERAL INFORMATION
OMM-0069_0E AERCO International, Inc.  100 Oritani Dr.  Blauvelt, NY 10913 Page 7 of 138
SP-100 Phone: 800-526-0288 PRI: 11/26/2013
1.2.1 Control Box Assembly
The front panel on the Control Box Assembly contains all of the display devices for the ECS/SP.
These include the Temperature Controller, an Over-Temperature Indicator/Switch and Boiler
Water In/Out Temperature Indicators.
The Temperature Controller is the “brain” of the ECS/SP which processes data received from
the temperature sensors. Using feed forward and PID (Proportional Integral Derivative)
algorithms, the Temperature Controller provides a 0 to 10 VDC control signal to the Control
Valve Actuator which precisely modulates the Control Valve for optimum DHW outlet
temperature control. The upper display on the front panel of the Temperature Controller displays
the current DHW outlet temperature. The lower display continuously displays the DHW setpoint
temperature currently stored in the Temperature Controller.
The Over-Temperature Indicator/Switch included in the Control Box constantly monitors and
displays the Water Heater outlet temperature to ensure the Heater does not exceed the preset
high temperature limit. The over-temperature limit is factory-set 20°F above the Heater setpoint
temperature specified on the sales order. If an over-temperature condition occurs, this device
sounds an audible alarm and cuts off power to the Control Valve Actuator thereby closing the
Control Valve and shutting off the boiler water flow to the SmartPlate Heater.
The Boiler Water In/Out temperatures are sensed on the surface of the copper inlet/outlet pipes
and are provided for informational and troubleshooting purposes only. They are not used for
temperature control but they do have alarm limits available for customer settings, if desired.
The Control Box components are housed in a steel enclosure with a hinged front door. This
door contains a clear polycarbonate window which permits maintenance personnel to view the
controls and displays of the Temperature Controller, and other display devices mounted on a
recessed panel behind the door. All sensor and control signal connections are made via cable
connections at the bottom of the Control Box. External AC power (120 VAC, 60 Hz, or 220 VAC,
50 Hz) is supplied via the cutout on the bottom of the Control Box. If desired, the Control Box
can be easily repositioned in 90° increments from its default position shown in Figure 1-1. Refer
to Chapter 2, paragraph 2.3.3 for details.
1.2.2 Feed-Forward Temperature Sensors
The Feed-Forward Temperature Sensor (Type J thermocouple) is installed in the cold water
inlet manifold on the Water Heater. The Temperature Sensor monitors a portion of the inlet flow
to the Heater and provides a feed-forward signal to the Temperature Controller which is
proportional to the change in flow through the Heater.
1.2.3 Outlet Temperature Sensors
The Control System includes a Dual Temperature Sensor which is installed in the hot water
outlet of the Water Heater. This sensor contains two identical Type J thermocouples. The first
thermocouple connects directly to the Temperature Controller to provide feedback PID control
for the outlet water temperature. The second thermocouple connects to the Over-Temperature
Indicator/Switch in the Control Box.
1.2.4 Boiler Water Inlet/Outlet Temperature Sensors
Two additional Temperature Sensors (Type J thermocouples) are provided with the Control
System. One Temperature Sensor is attached to the boiler water inlet and the other is attached
to the boiler water outlet of the SmartPlate Water Heater. These two Sensors are connected to
two identical Temperature Display Indicators in the Control Box to provide real-time indications
of the inlet and outlet boiler water temperatures. These Temperature Indicators are physically