Bard T36S1D, T42S1D, T48S1D, T60S1D Wall Mounted Package Heat Pump Instructions

Supplemental InstructionsModels:T36S1D, T42S1D, T48S1D, T60S1D

This model provides a unique dehumidification circuit for periods of high indoor humidity conditions.Additionally an “energy recovery ventilator” may be provided to allow for outside ventilation air requirements by eliminating excessive sensible and latent loads as a result of the increased ventilation requirement.Refer to Specification Sheet S3447 for the standard features of the base unit. Electrical data for the dehumidification models is different than the electrical data for the standard T**S1 models. Refer to Page 7 for the electrical data.

Dehumidification Circuit

The dehumidification circuit incorporates an independent heat exchanger coil in the supply air stream in addition to the standard evaporator coil.This coil reheats the supply air after it passes over the cooling coil, and is sized to nominally match the sensible cooling capacity of the evaporator coil.Extended run times in dehumidification mode can be achieved using waste heat from the refrigeration cycle to achieve the reheating process, while at the same time large amounts of moisture can be extracted from the passing air stream. Models that also have electric heaters installed have the electric heat inhibited during dehumidification mode, although it remains available for additional reheat during certain conditions. See below for specific operating sequences, and see attached are tables for performance on sensible and latent capacities, water removal ratings, and supply air delivery conditions.The dehumidification refrigerant reheat circuit is controlled by a 3-way valve directing the refrigerant gas to the normal condenser during periods when standard air conditioning is required. During periods of time of low ambient temperature (approximately 65° to 75° outdoor) and high indoor humidity, a humidistat senses the need for mechanical dehumidification. It then energizes both the compressor circuit and the 3-way valve, thus directing the hot refrigerant discharge gas into a separate desuperheating condenser circuit which reheats the conditioned air before it is delivered to the room. The refrigerant gas is then routed from the desuperheating condenser to the system condenser for further heat transfer. A small orifice inserted betweenthe reheat coil return line and the suction line will prevent liquid from accumulating in the reheat coil when it is inactive. This drain does not affect the normal operation of the system. A check valve is located in the reheat coil return line. It has a soft spring to hold the ball on the seat. Refer to Page 3 for the location of the check valve and drain back orifice. When the humidistat is satisfied, the system automatically switches back to normal A/C mode and either continues to operate or turns off based on the signal from the wall thermostat. The result is separate humidity control at minimum operating cost.

Dehumidification Sequence of Operation

Dehumidification is controlled through the thermostat (if capable) or through a separate humidistat. On a call for dehumidification mode of operation, the compressor and 3-way valve that feeds the reheat coil are energized through circuit R-W3. Dehumidification will continue until the humidistat is satisfied. If the room temperature falls below 1 st stage heating setpoint, electric heat will be energized by the room thermostat and cycle to maintain room temperature.If the 2 and stage heating setpoint is reached, the dehumidification cycle is de-energized and the heat pump heating is energized.If the mixed air (return and ventilation, if used) temperature (measured at the internal filter location) drops below 65°F during the dehumidification cycle, electric heat will cycle to help maintain room temperature to the 65°F condition.Anytime there is a call for an R-Y circuit, dehumidification is canceled and the unit will operate until satisfied.If the dehumidification call is still present when the R-Y call is satisfied, the unit will continue to operate and revert to dehumidification mode.
T36S1D Application Performance Data
IndoorConditions Outdoor System Capacity Pounds ofWater/Hour EvaporatorAirflow ApproximateSupply Air Mode
DB/WB  % RH  DB Total Sensible Latent S/T Lbs. CFM DB/WB A/C vs. Dehum
65/63 90 65 39,773 17,117 22,656 0.43 21.37 1100 51.3 / 51.0 A/C
65/63 90 65 20,483 (-1,612) 22,095 0 20.84 1100 66.2 / 57.5 Dehum
75/62.5 50 75 37,395 28,861 8,534 0.77 8.05 1100 51.4 / 50.6 A/C
75/62.5 50 75 13,111 6,588 6,523 0.5 6.15 1100 69.6 / 58.6 Dehum
75/65.5 60 75 39,695 25,159 14,536 0.63 13.71 1100 54.5 / 53.9 A/C
75/65.5 60 75 17,009 3,586 13,423 0.21 12.66 1100 72.0 / 60.9 Dehum
75/68 70 75 41,414 22,024 19,390 0.53 18.29 1100 57.1 / 56.6 A/C
75/68 70 75 18,168 957 17,211 0.05 16.24 1100 74.2 / 63.6 Dehum
80/67 50 95 2,594 (-487) 3,082 0 2.91 1100 80.4 / 66.2 Dehum
T42S1D Application Performance Data
IndoorConditions Outdoor System Capacity Pounds ofWater/Hour EvaporatorAirflow ApproximateSupply Air Mode
DB/WB % RH DB Total Sensible Latent S/T Lbs. CFM DB/WB A/C vs. Dehum
65/63 90 65 44,438 18,907 25,531 0.43 24.09 1100 51.8 / 51.2 A/C
65/63 90 65 20,765 (-587) 21,352 0 20.14 1100 65.5 / 57.9 Dehum
75/62.5 50 75 40,262 31,532 8,730 0.78 8.24 1100 52.3 / 51.2 A/C
75/62.5 50 75 13,136 7,555 5,581 0.58 5.27 1100 69.8 / 59.1 Dehum
75/65.5 60 75 42,824 27,116 15,708 0.63 14.82 1100 55.4 / 54.4 A/C
75/65.5 60 75 15,544 4,489 11,055 0.29 10.43 1100 71.8 / 61.8 Dehum
75/68 70 75 45,445 24,140 21,305 0.53 20.1 1100 57.9 / 57.1 A/C
75/68 70 75 19,977 1,667 18,310 0.08 17.27 1100 73.9 / 63.6 Dehum
80/67 50 95 5,289 (-216) 5,505 0 5.19 1100 80.2 / 65.7 Dehum

Values shown in ( ) are BTUH of heat available at these conditions

T48S1D Application Performance Data
IndoorConditions Outdoor System Capacity Pounds ofWater/Hour EvaporatorAirflow ApproximateSupply Air Mode
DB/WB  % RH  DB Total Sensible Latent S/T Lbs. CFM DB/WB A/C vs. Dehum
65/63 90 65 53,748 22,691 31,057 0.42 29.3 1100 51.9 / 51.4 A/C
65/63 90 65 28,218 (-1,638) 29,856 0 28.17 1100 66.1 / 57.3 Dehum
75/62.5 50 75 49,295 38,697 10,598 0.79 10 1100 52.5 / 51.6 A/C
75/62.5 50 75 20,207 9,819 10,388 0.49 9.8 1100 69.3 / 58.3 Dehum
75/65.5 60 75 52,392 33,593 18,799 0.64 17.73 1100 55.5 / 54.7 A/C
75/65.5 60 75 24,015 5,714 18,301 0.24 17.27 1100 71.7 / 60.9 Dehum
75/68 70 75 55,457 29,604 25,853 0.53 24.39 1100 57.8 / 57.1 A/C
75/68 70 75 27,428 2,150 25,278 0.08 23.85 1100 73.7 / 63.0 Dehum
80/67 50 95 11,243 1,576 9,667 0.14 9.12 1100 79.1 / 64.9 Dehum
T60S1D Application Performance Data
IndoorConditions Outdoor System Capacity Pounds ofWater/Hour EvaporatorAirflow ApproximateSupply Air Mode
DB/WB  % RH  DB Total Sensible Latent S/T Lbs. CFM DB/WB A/C vs. Dehum
65/63 90 65 62,312 27,363 34,949 0.44 32.97 1650 50.1 / 49.9 A/C
65/63 90 65 33,100 (-289) 33,389 0 31.5 1650 65.2 / 56.6 Dehum
75/62.5 50 75 57,542 44,209 13,333 0.77 12.58 1650 51.0 / 50.1 A/C
75/62.5 50 75 26,138 12,483 13,655 0.48 12.88 1650 68.2 / 57.2 Dehum
75/65.5 60 75 61,912 38,922 22,990 0.63 21.69 1650 53.7 / 53.2 A/C
75/65.5 60 75 30,827 7,749 23,078 0.25 21.77 1650 70.8 / 59.8 Dehum
75/68 70 75 65,315 34,612 30,703 0.53 28.97 1650 56.0 / 55.6 A/C
75/68 70 75 34,303 3,483 30,820 0.1 29.08 1650 73.0 / 62.1 Dehum
80/67 50 95 17,289 2,543 14,746 0.15 13.91 1650 78.5 / 63.9 Dehum

Values shown in ( ) are BTUH of heat available at these conditions

TABLE 1Dehumidification Relay Logic Board

Energize on UnitTerminal Strip Mode Occupied/Unoccupied Inputs to the Board Outputs from the Board
RAT Y B W2 Al D G G1 BK RV TWV W YO A2
Y, G 1st Cooling Unoccupied X X X X X
Y, G, 01 1st Cooling Occupied X X X X X X X
Y, G, W3, 01 1st Cool/Dehum Occupied X X X X X X X X
Y, G, W3 1st Cool/Dehum Unoccupied X X X X X X
Y, Yl*, G 2nd Cooling Unoccupied X X X X X
Y, Yl*, G, 01 2nd Cooling Occupied X X X X X X X
Y, Yl*, G, 01, W3 2nd Cool/Dehum Occupied X X X X X X X X
Y, Y1*, G, W3 2nd Cool/Dehum Unoccupied X X X X X X
Y, G, B 1st Heating Unoccupied X X X X X X X
Y, G, B, 01 1st Heating Occupied X X X X X X X X X
Y, G, B, 01, W3 1st Heat/Dehum Occupied X X X X X X X X X X X
V, G, B, W3 1st Heat/Dehum Unoccupied X X X X X X X X
V, Yl*, B, G 2nd Heating Unoccupied X X X X X X X
Y, Y1*, B, G, 01 2nd Heating Occupied X X X X X X X X X
Y, Yl*, B, G, 01, W3 2nd Heat/Dehum Occupied X X X X X X X X X X X
Y, Y1*, B, G, W3 2nd Heat/Dehum Unoccupied X X X X X X X X
Y, Y1*, G, B, W2 3rd Heating ** Unoccupied X X X X X X X X X
Y, Yl*, G, B, W2, 01 3rd Heating ** Occupied X X X X X X X X X X X
Y, Yl*, G, B, W2, 01, W3 3rd Heating ** Occupied X X X X X X X X X X X X
Y, yr, G, B, W2, W3 3rd Heating ** Unoccupied X X X X X X X X X X
B, W2, E***, G Emergency Heat Unoccupied X X X X X X X
B, W2, E***, G, 01 Emergency Heat Occupied X X X X X X X X X
B, W2, E***. G, 01, W3 Emergency Heat/Dehum Occupied X X X X X X X X X
B, W2, E***, G, W3 Emergency Heat/Dehum Unoccupied X X X X X X X
W3 Dehum Unoccupied X X X X
W3, 01 Dehum Occupied X X X X X X
W3, 01, RAT Closed Dehum/RAT Occupied X X X X X X X X X
W3, RAT Closed Dehum/RAT Unoccupied X X X X X X X

* Y1 directly energizes the compressor solenoid; it does not go through the dehum board.** Is only applicable to units with strip heat.*** Is directly energized at the terminal strip of the unit; it does not go through the dehum board.

TABLE 2Electrical Specifications

 

  1. These “Minimum Circuit Ampacity” values are to be used for sizing the field power conductors. Refer to the National Electrical Code (latest version), Article 310 for power conductor sizing.CAUTION: When more than one field power circuit is run through one conduit, the conductors must be derated. Pay specialattention to note 8 of Table 310 regarding Ampacity Adjustment Factors when more than three (3) current-carrying conductors are in a raceway.
  2. Maximum size of the time delay fuse or circuit breaker for protection of field wiring conductors.
  3. Based on 75°copper wire. All wiring must conform to the National Electrical Code and all local codes.
  4. The maximum KW that can operate with the heat pump on is 4KW. Full heat available during emergency heat mode.
  5. The maximum KW that can operate with the heat pump on is 10KW. Full heat available during emergency heat mode.
  6. The maximum KW that can operate with the heat pump on is 9KW. Full heat available during emergency heat mode.
  7. The maximum KW that can operate with the heat pump on is 8KW. Full heat available during emergency heat mode.

NOTE: The Maximum Overcurrent Protection (MOCP) value listed is the maximum value as per UL 1995 calculations for MOCP (branch-circuit conductor sizes in this chart are based on this MOCP). The actual factory-installed overcurrent protective device (circuit breaker) in this model may be lower than the maximum UL 1995 allowable MOCP value, but still above the UL 1995 minimum calculated value or Minimum Circuit Ampacity (MCA) listed.

IMPORTANT: While this electrical data is presented as a guide, it is important to electrically connect properly sized the fuses and conductor wires in accordance with the National Electrical Code and all local codes.

Bard Manufacturing Company, Inc.Bryan, Ohio 43506www.bardhvac.comManual: 7960-640ESupersedes: 7960-640DDate: 5-14-21

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