Carrier INDUCTION AIR TERMINALS 36S Manuel d'utilisateur télécharger pdf (Page 17)

Controls and control systems

36R series terminal units

The 36R Series units are available with system-powered,

self-contained controls. These controls operate with wall or

unit-mounted, bi-metallic, bleed-type thermostats having a

65 to 85 F operating range and a throttling range of

±1.5 F.

The power source for system powered controls is plenum

pressure. The minimum pressure for satisfactory operation

is 1.5-in. wg. System-powered controls can be used in ei-

ther changeover or non-changeover system applications.

Changeover system — This system automatically

switches from cooling to heating mode and reverse, de-

pending upon the coil water temperature.

Control air from the plenum passes thru a final filter and

restrictor tee to the common port of a changeover valve.

Here, a bimetallic element determines whether the control

air will flow to the cooling bleed port or the heating bleed

port of the thermostat.

In the Cooling mode, the unit coil contains water at 65 F

or below. At these temperatures, the bimetallic element in

the changeover valve blocks off the heating port and allows

control air to flow to the cooling bleed port of the thermo-

stat. When the thermostat calls for cooling, the thermostat

opens up the cooling bleed port. Control air now bleeds

from the system. The bellows begins to deflate and the by-

pass damper is allowed to modulate open.

More room air circulates over the cooling coil and room

temperature lowers as required. When the thermostat is

satisfied, the thermostat again restricts the cooling bleed

port. The bellows begins to inflate, closing down the damp-

er and allowing less room air to circulate over the cooling

coil.

In the Heating mode, the unit coil contains warm (85 F or

above) water. The changeover valve bimetal blocks off the

cooling port and allows control air to flow to the heating

bleed port of the thermostat. On call for heating, the ther-

mostat opens up the heating bleed port. Control air bleeds

from the system. The bellows deflates and the bypass

damper opens up. More room air circulates over the warm

coil, raising the room temperature as required.

Non-changeover system — In this system, the unit op-

erates in a manner similar to the changeover system ex-

cept that control air passes directly from the restrictor tee

to the cooling bleed port of the thermostat.

36TE terminal units

These units operate in the same manner as the non-

changeover system of 36R units. The 36TE units, howev-

er, also have electric heat.

When the thermostat drops below its –1.5 F throttling

range, causing the bypass damper to close completely, the

damper actuates a microswitch that energizes the electric

heater.

The heaters are designed to operate at 208, 240 or 277

volts as specified. As a fail-safe, the electric heater is deac-

tivated whenever the supply air fan shuts off and the by-

pass damper reverts to its normally open position.

FILTER AND

RESTRICTOR TEE

ASSEMBLY

THERMOSTAT

WARMER

COOLER

COOLING MODE

FILTER

BELLOWS

CHANGEOVER

VALVE

BIMETAL

HEATING MODE

TYPICAL 36R CHANGEOVER SYSTEM

a36-522

Application data

1 2 ... 12 13 14 15 16 17 18 19 20 21 22 ... 25 26

Commentaires sur ces manuels

Pas de commentaire

Carrier INDUCTION AIR TERMINALS 36S Manuel d'utilisateur Page 17

Commentaires sur ces manuels

Produits connexes et manuels pour Climatiseurs à système divisé Carrier INDUCTION AIR TERMINALS 36S