Enertech AV Series - Components

Enertech Global, LLC 47
AV : MD/ME - Rev. A Models
Installaon and Operaons Manual
Components

Touch screen where current status can be observed and
sengs of the system can be changed, described in addional
detail in this secon. This is the master controller which
communicates via RS-485 with the ASB and outdoor unit.
Field Wiring and RS-485
The eld wiring blocks provide dry contact inputs for
connecon to zone controllers (see Secon 8). These inputs
provide calls for Heang, Cooling, High Heang, and Hot
Water.

The ASB is a secondary controller to the HMI (primary
controller) and provides inputs for sensors and outputs
to actuators for the Indoor Module. The inputs include
thermistors, ow meter, and pump feedback. It controls
actuators, including pump speed (via PWM), electric heater
stages, and the three way valve. 24VAC from the transformer
is fed into the ASB for use on these outputs.
ACB Companion Board
The Companion Board is an IO expander for the ASB. The
dry contact inputs on the eld wiring in input into this board.
Addionally, it provides stable 12VDC supply for the ASB and
HMI from input line voltage.
Thermistors
Two thermistors are ulized on the Indoor Module to
measure entering and leaving load temperatures. Through
these measurements the temperature dierence (Delta-T)
is calculated and provides the ideal pump speed. Reference
Secon 12 for resistance values.
Flow Sensor
The ow meter provides an accurate measurement of GPM
through the load circuit. It is used for modulaon of pump,
ensuring minimum ow in all condions. They are also used
for simple readouts on the HMI as well as ow faults and
alarms.
Secon 8: Controls