Anti-short Cycle Timer, First Stage Cooling

036-21342-002 Rev. E (0505)

SYSTEM OPERATION

This heat pump model is equipped with both YorkGuard V heat pump control and TS compressor control. The interface control 6CF board is used to bypass the first stage of heat when the outdoor temperature falls below certain tempera- tures. The TS control board is used only to switch between 1 and 2 cylinder operation. The fault codes and pressure switch on the TS control board are bypassed using the jumpers between the test and "PS" pins.

1.Anti-short Cycle Timer

The five-minute time delay on YorkGuard V will be used to prevent the system from short cycling after the ther- mostat off or power interrupt. This time delay can be bypassed by temporarily shorting the test terminals on YorkGuard V for 3 seconds. Since a jumper was factory installed across the test pins on the TS control board, the anti-short cycle timer on the TS control board is bypassed.

2.First Stage Cooling

This heat pump model is equipped with a Twin-Single compressor. With a call for first stage cooling, the com- pressor operates one cylinder. The run winding (R) is connected through the upper left contactor (A) and to the capacitor and the start winding (S) is connected to line voltage. The system operates at low discharge pressure and high suction pressure.

3.Second Stage of Cooling

With a call for second stage cooling, the TS control will shut the compressor off for two seconds then energize relays R1 and R2 on the TS control board. This will de- energize (open) the upper left contactor (A) and energize (close) the lower right contactor (B), connecting the com- pressor run winding (R) to the line voltage and start winding (S) to the capacitor. The compressor runs in the reverse direction with two cylinders compared to the first stage. The system will operate with two cylinders until both first and second stage are satisfied. The Y2OUT signal from the relay board causes the indoor blower to function at high speed.

If the room thermostat calls for second stage cooling (Y2) on two consecutive cooling cycles, the next call for cooling for either first or second stage will energize the unit in second stage mode. The above mode will be reset to permit start up on the first stage with only a Y1 call when the second stage operation cycle runs less than 15 minutes or when 24V to the TS control board is discon- nected.

4.6K Relay on the 6CF Control Board

The 6K relay on the 6CF interface board operates as fol- lows. See Figure 1:

a.If the YorkGuard V defrost control balance point set- ting is 45°F, the 6K relay will be:

•Energized if liquid temperature goes below 35°F.

•De-energized if the liquid temperature goes above 35°F AND the ambient is greater than 42°F for five minutes AND the unit is not in defrost.

b.If the YorkGuard V defrost control balance point set- ting is at anything but 45°F, the 6K relay will be:

•Energized if liquid temperature goes below 45°F.

•De-energized if the liquid temperature goes above 45°F AND the ambient is greater than 55°F AND the unit is not in defrost.

5.Heating mode with the de-energized 6K relay

The TS compressor operates similar to the first and sec- ond stage of cooling modes except there is no O input from the thermostat, the reversing valve is not energized, and the system operates in heating heat pump mode. The YorkGuard V control and the liquid temperature will not allow the system to go into the defrost mode.

6.Heating mode with the energized 6K Relay

The energized 6K relay on the interface board (6CF) will connect Y1 and Y2 and disconnect Y2OUT from the TS control to the indoor blower if the J1 pin is not in the ON position. The compressor will operate only in second stage regardless of the first or second stage call from the thermostat. The indoor blower will operate in low air mode. The indoor discharge air temperature should be about 10°F hotter than a normal heat pump. If high- speed air is preferred, move J1 pin to the ON position at the interface board (6CF). This will send the Y2OUT sig- nal back to the indoor blower for the high speed air.

	Y2	Y2 OUT	24V (R) FROM
			24V (R) FROM
			YORKGUARD
	6K		6K
	NC		6K
	NC
			NC
			J1
		6K
		NO
R	Y2	Y1	Y2 OUT

FIGURE 1 : 6CF Interface Board

2	Unitary Products Group

E4TS030 THRU 060 specifications

The York E4TS030 through E4TS060 are a series of air-cooled chillers designed for commercial and industrial applications. These chillers are renowned for their high efficiency, reliability, and advanced technology, making them a popular choice among HVAC professionals and building managers.

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In terms of control technology, the E4TS series is equipped with advanced microprocessor controls that facilitate precise temperature management and system diagnostics. The intuitive interface allows operators to monitor the system’s performance in real-time, optimizing efficiency and helping to prevent potential issues before they escalate.

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Furthermore, the York E4TS series supports various refrigerant options, including environmentally friendly refrigerants, aligning with global initiatives to reduce greenhouse gas emissions. This flexibility enables users to select a refrigerant that meets their specific environmental goals and regulatory requirements.

In summary, the York E4TS030 THRU 060 chillers present a winning combination of energy efficiency, compact design, advanced controls, and low noise operation. Their robust construction and commitment to sustainability make them an excellent choice for a wide range of commercial cooling applications, ensuring optimal performance and reliability over their lifespan.

York E4TS030 THRU 060 Anti-short Cycle Timer, First Stage Cooling, Second Stage of Cooling

Models: E4TS030 THRU 060