AHU ControlDuct type 2-pipe cooling, electric heater & dehumidification

ATC Application HandbookSection 2

Issue Date 0500

Equipment Wiring

Operation Description

Proportional plus integral temperature controller (TC-1)together with remote duct temperature sensor (TE-1)provides modulating control for the motorized coolingvalve (TV-1), so as to maintain the desired return airtemperature.

Temperature controller (TC-1) also provides comfort/Standby mode selection button and set point dial.

Electronic humidistat (HS-1) together with remote ducthumidity transmitter (HE-1) provides dehumidification.Once the return air R.H. increases above the set point,the cooling valve (TV-1) will be driven to its fully openposition.

Electronic heating thermostat (TS-1) together with itsassociated stage modules (SM-1) and remote ducttemperature sensor (TE-2) provide on-off control of the3 stages electric heater bank to reheat the supply air.

A high limit cutout thermostat with manual reset (HL-1) isinstalled to de-energise the electric heaters in the event ofexcessive high temperature built up in the supply air duct.Air flow switch (FS-1) provides safety interlock such thatelectric heaters can only be energised when the fan running.

The controller interlocks with the supply fan status, so that onfan shut down, the controller will be switched off, the coolingvalve will be driven to its closed position, and the heaters willbe de-energised.

The differential pressure switch (DPS-1) monitors the status offilter, when the set point is exceeded, a signal will be given toswitch on 'filter change' indicating lamp on the control panel.

The smoke detector (SD-1) monitors the smoke status. Oncesmoke is detected, the fan will be shut down.

AHU-3

AHU ControlDuct type 2-pipe cooling, electric heater & dehumidification

ATC Application HandbookSection 2

Issue Date 0500

Equipment List

AHU-3

Note:

1. R: Relay contact interlock with blower.

2. Refer to DH100 wiring diagram for wiring the smoke detector.(Attached at the end of this section)

3. If 3 way mixing valve instead of 2-way valve is used, thewiring at terminals 2 & 3 of the actuator TV-1 should beinterchanged.

4. More stage modules can be connected to TS-1, for details,please refer to system 27 catalogue.

5. The jumper setting for directed or reversed control in TS-1 ,SM-1 and HS-1should be refer to installation sheet.

Instr. No. Code No. Description

TE-1 TS-9104-8220 Duct type temp. sensor

TC-1 TC-8903-1132-WK 12/28 C, PI analogue controller, remote sensor, 24V

TE-2 A99DY-200C Duct temperature sensor

TS-1 A27A1N11 -40/40 C, din-railmount electronic thermostat, 24VAC

SM-1 S27A1 Din-railmount stage module,24VAC

HL-1 A25AN-9 Hi-limit cutout, manual reset, 237mm

FS-1 F62AA-8 Air flow switch

HE-1 HT-9000-1D1 Duct type humidity transmitter

HS-1 W27N11 10/90% din-railmount humidity controller,24VAC

SD-1 DH100ACDCP Duct type smoke detector (Photo)

ST-3 Sampling Tube

DPS-1 P32AC-2 0/5" W.C. differential pressure switch

X-1 Y62HKL-40 Transformer, 40VA, 240/220/24V

TV-1 Refer to Valve Schedule (Section 3) Valve & Valve Actuator with 24 VAC power supply