Carrier 30RQ 039 Series Installation, Operation And Maintenance Instructions

Contents

3614.4 - Supplementary electric resistance heatersTo permit staging of the capacity reduction of the heat pumpat low ambient temperatures, as shown in the diagram below,it is possible to install supplementary electric heaters in theleaving water line. Their capacity can compensate for thecapacity drop of the heat pump.These heaters can be controlled via an electronic cardmounted on a board (option).Four outputs are available to control the heater contactors(not supplied with the board), permitting gradual compen-sation of the heat pump capacity reduction.These outputs are configurable to obtain a choice of two,three or four stages. The last stage will only be activatedafter a shut-down of the heat pump following a fault con-dition (safety device).In the diagram below “example of additional electricheaters” the capacity of the four heaters is the same as thecapacity of the heat pump at 7°C outdoor air temperature.This requires only a 400 V-3 ph-50 Hz power supply source,as well as a connection to the unit via a communication bus.For the required configuration of the stages consult the30RB/RQ 017-160 Pro-Dialog+ Control IOM.legend1 Electric heater power supply 400 V-3 ph-50 Hz2 Accessory control board for four additional electric heaters3 Internal communication bus4 Heater stage control contactors5 Power supply for additional heaters6 Supplementary electric resistance heatersTypical accessory installation diagramlegend1 Stage 12 Stage 23 Stage 34 Stage 4A Heat pump capacity variation as a function of the air temperatureB Building thermal loadC Balance point between the capacity supplied by the heat pump and the thermal load of the buildingOperating range, in which the heat pump capacity is lower than the building thermal loadOperating range, in which the heat pump capacity is higher than the building thermal loadOutdoor air temperature, °CPump capacity, %Example of additional electric heaters1A234B120100806040200-15 -10 -5 0 5 10 15112C123465