Carrier 50PEC09-18 specifications Coaxial Water Pressure Drop, Gpm

b. Select Weekly, then press enter (7 schedules available).

c.Select day and press enter.

d.Press enter again and select ADD or DEL (DECR or INCR) set schedule.

e.Enter ON/OFF time, then press continue.

f.Press OK to apply and save to a particular day of the week.

g.Continue to add the same or different schedule spe- cific days of the week.

To add exceptions to the schedule:

i.Press Add softkey.

ii.Select exception type from following:

•Date

•Date Range

•Week-N-Day

•Calender Reference

9.Go back to Home Screen.

10.Remove BACview6 cable from SPT sensor by reversing the process in Step 1.

11.Perform system test.

Flow Regulation — Flow regulation can be accom- plished by two methods. Most water control valves have a built-in flow adjustment valve. Determine the flow rate by measuring the pressure drop through the unit heat exchanger. See Table 12. Adjust the water control valve until a flow of 1.5 to 2 gpm per ton cooling is achieved. Since the pressure constantly varies, two pressure gages may be needed.

An alternative method for regulating flow is to install a flow control device. These devices are typically an orifice of plastic material mounted on the outlet of the water control valve, designed to allow a specified flow rate. Occasionally these valves produce a velocity noise that can be reduced by

applying some back pressure. To accomplish this, slightly close the leaving isolation valve of the water regulating device.

CAUTION

DO NOT use “Stop Leak” or any similar chemical agent in this system. Addition of these chemicals to the loop water will foul the system and inhibit unit operation.

Antifreeze — In areas where entering loop temperatures drop below 40 F or where piping will be routed through areas subject to freezing, antifreeze is needed.

Alcohols and glycols are commonly used as antifreeze agents. Freeze protection should be maintained to 15 F below the lowest expected entering loop temperature. For example, if the lowest expected entering loop temperature is 30 F, the leaving loop temperature would be 22 to 25 F. Therefore, the freeze pro- tection should be at 15 F (30 F –15 F) = 15 F.

IMPORTANT: All alcohols should be pre-mixed and pumped from a reservoir outside of the building or intro- duced under water level to prevent alcohols from fuming.

Calculate the total volume of fluid in the piping system. See Table 13. Use the percentage by volume in Table 14 to deter- mine the amount of antifreeze to use. Antifreeze concentration should be checked from a well mixed sample using a hydrome- ter to measure specific gravity.

FREEZE PROTECTION SELECTION — The 30 F FP1 fac- tory setting (water) should be used to avoid freeze damage to the unit.

Once antifreeze is selected, the JW3 jumper (FP1) should be clipped on the control to select the low temperature (antifreeze 10 F) set point to avoid nuisance faults.

Table 12 — Coaxial Water Pressure Drop

						PRESSURE DROP (ft wg)
UNIT		FLOW		30 F		50 F		70 F		90 F
50PEC		(GPM)	Without	With Cv = 2.9	Without	With Cv = 2.9	Without	With Cv = 2.9	Without	With Cv = 2.9
			Motorized	MOPD = 125 psi	Motorized	MOPD = 125 psi	Motorized	MOPD = 125 psi	Motorized	MOPD = 125 psi
			Valve		Valve		Valve		Valve
		1.3	1.8	2.0	1.3	1.5	1.2	1.3	1.0	1.2
09		1.9	3.2	3.6	2.5	2.9	2.2	2.7	2.0	2.4
		2.5	5.0	5.8	3.9	4.6	3.5	4.2	3.0	3.8
		1.6	1.8	6.5	1.6	6.5	1.4	6.5	1.3	6.5
12		2.3	3.3	11.4	2.9	11.4	2.6	11.4	2.3	11.4
		3.1	5.3	19.6	4.5	19.6	4.1	19.6	3.7	19.6
		1.8	1.2	1.6	1.2	1.6	1.1	1.5	1.0	1.4
15		2.7	2.6	3.4	2.2	3.1	2.0	2.9	1.9	2.7
		3.6	4.2	5.7	3.5	5.0	3.2	4.8	3.0	4.5
		2.4	2.1	2.8	2.0	2.6	1.8	2.4	1.6	2.3
18		3.6	4.2	5.8	3.7	5.2	3.3	4.9	3.0	4.6
		4.8	6.8	9.6	6.0	8.8	5.5	8.2	4.9	7.7
			LEGEND
Cv	— Flow Coefficient
MOPD — Maximum Operating Pressure Differential

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