Operating Instructions

Table Of Contents

The Controller

Siemens Building Technologies, Inc. 1-3

The ATEC with Reheat model (Figure 1-2) is designed to control terminal boxes, either single

duct or fan powered (series or parallel), with hot water reheat or up to two stages of electric

reheat. It includes Applications 2500, 2501, 2522, 2523, 2524, and 2526. It has removable

terminal blocks for FLN, I/O, and power terminations. An Autozero Module can be used with

this controller for Applications 2500, 2501, and 2522. An Autozero Module is required for

applications where continuous airflow is required for an area.

EHC

24 VAC

Air Velocity

Sensor

Room Temperature

Sensor Connection

I/O

Connections

FLN Connection

Power

Connection

BST/FLN LED

TEC0436R1

Figure 1-2. Actuating Terminal Equipment Controller (ATEC)—VAV with Reheat.

Digital Inputs

Both models of the controller have Digital Input (DI) 1. DI 1 is associated with the room-

temperature-sensor cable (specifically, the sensor's override switch) and is displayed on

screen as DI OVRD SW (Point 19). This DI cannot be wired is and not available for use as an

auxiliary point.

In addition to DI 1, the ATEC with Reheat has DI 3 (terminals 4 and 5) and DI 4 (terminals 5

and 6) These inputs are typically used to monitor the status of a dry contact such as a switch

or an auxiliary contact. DI 4 can be used with a wall switch that changes the controller from

day mode to night mode and back again. See Chapter 3—Applications for ATEC—VAV with

Reheat for more information.

NOTE: In all applications for the ATEC with Reheat, the inputs labeled "AI 3" and “AI 4”

on the controller can each be used either as a DI point or as an Analog Input (AI)

point, but neither can be used for both at the same time.