York YPAL 050, YPAL 061, YPAL 051, YPAL 060 Service, Temperature Sensors, Duct Pressure Transducer

FORM 100.50-NOM6 (1207)

SECTION 8 – SERVICE

ANALOG INPUT OPERATION Duct Pressure Transducer

This section describes the control operation of the (29) twenty-nine analog inputs. These inputs are used by the control to monitor and respond to unit temperatures, pressures, enthalpy, etc. The location of each of these connections on the Unit Controller is contained in Table 8-8. Notice that the ID gives the jack connection designated as “J” and then the identifying number of the connector, followed by a – and then the pin number of the connector. For example the SUPPLY AIR TEMPERATURE analog input would be found at J1-1. This is connector J1 – Pin 1. As the Unit Control board is positioned in the control box the top row of the J series connectors is the input, the middle row is the common, and the bottom row is the 5 VDC input to the sensor. Also the pin in the right hand top corner is pin 1.

Temperature Sensors

The temperature sensors are all 10KType IIIThermistors. The relationship between the temperature and the voltage output and resistance is contained in Table 8-1

.The following analog input are of this type: Supply Air Temperature, Heat Entering Temp, Flex Evap Temp, Outside Air Temp, Return Air Temp, Suction Temp #1, Suction Temp #2, Zone Temp, and Under Floor Temp.

The Duct Pressure Transducer is located behind the right hand damper door. The purpose of the transducer is to sense and convert the static pressure in the supply-side of the duct to a 0 to 5 volt DC voltage. The DC voltage is sent to the Unit Controller and compared against the “DUCT STATIC PRESS ACTIVE SP”. The transducer is factory wired, but pneumatic tubing must be field supplied and installed (refer to Section 2 “INSTALLATION” in this manual). The Duct Static Pressure Transducer measures differential pressure between the pressure in the duct and atmospheric pressure. When verifying transducer operation, the technician must insert a tee in the pneumatic tubing and connect a manometer to the tee to verify the pressure being applied to the transducer. Once this pressure is known, a comparison can be made of the duct pressure vs. output volts DC from the transducer. Table 8-2 shows the relationship between the pressure applied to the duct pressure transducer and the output voltage. The output is linear between 0" WC and the SPAN. The “DUCT PRESS TRANSDUCER SPAN” can be set to 1.25, 2.5 or 5" WC. The “DUCT PRESS TRANSDUCER SPAN” must always be set based on the span of the transducer installed.

TABLE 8-1 – TEMPERATURE SENSOR RESISTANCE

°F	VOLTAGE	RESISTANCE	°C	°F	VOLTAGE	RESISTANCE	°C
				55	2.36	16,744	12.78
-25	0.49	139,639	-30.6
				60	2.51	14,681	15.56
-20	0.53	127,453	-28.9
				65	2.66	13,216	18.33
-15	0.60	109,624	-26.1
				70	2.80	11,771	21.11
-10	0.69	94,519	-23.34
				75	2.94	10,502	23.89
-5	0.78	81,665	-20.55	80	3.08	9,388	26.67
				85	3.21	8,404	29.45
0.0	0.88	70,750	-17.78
				90	3.33	7,537	32.22
5	0.98	61,418	-15.00
				95	3.45	6,770	35.0
10	1.10	53,426	-12.22
				100	3.56	6,090	37.78
15	1.22	46,582	-9.44
				105	3.66	5,487	40.56
20	1.35	40,703	-6.67
				110	3.76	4,951	43.34
25	1.48	35,639	-3.89
				115	3.85	4,475	46.11
30	1.62	31,269	-1.11
				120	3.94	4,050	48.89
35	1.77	27,490	1.67
				125	4.02	3,671	51.66
40	1.91	24,219	4.44
				130	4.09	3,332	54.44
45	2.06	21,377	7.22
								8
				135	4.16	3,029	57.22
50	2.21	18,900	10.00

JOHNSON CONTROLS 153