Carrier 38HB series Installation, Operation And Maintenance Instructions

Contents

Carrier 38HB series Installation, Operation And Maintenance Instructions Manual pdf 12 page image

9. SAFETY ELEMENTSClogged filter detector (optional)Differential pressostat for indication, through an automatic reset alarm,of a level of dirtiness of the filters greater than the established level.This pressostat is installed in the factory in the indoor unit.Control of air flow (optional)A differential pressostat can be incorporated in order to measure thevariation in air flow. This pressostat allows the detection of fan beltbreakages, since the fan relay only detects operating faults that havearisen in the motor. This safety device is included in units with electricalheaters. This pressostat is installed in the factory in the indoor unit.10. OPTIONALConde nsat ion pre ssure c ont rol (38HB/HF)This control is advisable for outdoor units 38HB/HF that work in coolingwith an outdoor temperature below 15ºC.In units with centrifugal fan a check is performed per damper in the fansupply. A servomotor opens or closes the damper depending on theproportional signal 0-10V received from the electronic control system.V-220004DamperServomotorThe installation of some of these options brings in pressuredrops at air level therefore this must be considered whenselecting fans.The pressure drop graphs in the options, can be seen in thetechnical brochure.High pressure pressostatConnected to the compressor discharge, it willstop its operation when the pressure at that pointreaches the setpoint. It disconnects at 42 bar andit is automatically reactivated.Low pressure pressostatWhen connected to the compressor suction, itwill stop its operation when the pressure at thatpoint goes down below the tare value (causedby obstructions in the circuit, excessive dirt in thefilters, fan stop or ice formation in the evaporator).This pressostat disconnects at 2 bar and is automatically reactivated.Safeties at the compressorThe scroll type compressor that these units as standard have thefollowing safeties:- Non-return valve built into the compressor.- Temperature probe for the discharge from the compressor to protectthe unit with discharge temperatures greater than 135ºC.Defrost controlThis safety device is intended to eliminate ice which could accumulate inthe outdoor coil when the unit is working in the heating cycle. Defrostingis carried out by the control depending on the value measured by thesensor(s) on the outdoor coil(s) and the time set between defrostingoperations.Magnetothermals for line protectionThey are located at the beginning of the power lines for thecompressor(s) and motor fan(s) to protect them.Automatic switch in the control circuitMagnetothermal switch that protects the operation circuit againstcontinuous surges as well as against high currents of short duration(short circuits).Main door switchBy using a mechanical device, it impedes access to the electric panelwhen the unit is with voltage.Anti-fire safetyWith the optional return air probe, the electronic control can activate ananti-fire safety device that detains the unit when the return air surpassesa temperature of 60°C (by default). It cannot return to operation untilthe temperature has dropped to below 40ºC.Split-system cooling unitsand heat pumps12