Danfoss Condensing units Service guide

Fitters’ Notes	Condensing units
Contents		Page
	General information on operating Danfoss condensing units . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .	. . . .3. . .
	Equipment configuration . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .	. . . .3. . . . . . .
	Power supply and electrical equipment . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .	. . .3. . . . . .
	Hermetic compressors . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .	. . . 4
	Condensers and fans . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .	. . . .4. . . . . . .
	Stop valves . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .	. . . 4
	Receiver Pressure container ordinance . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .	. . .5. . . . . .
	Terminal box . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .	. . . 5. . . . . .
	Safety pressure monitors . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .	. . . .5. . .
	Setup . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .	. . . 5. . . . . . .
	Protective weather-proof housing . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .	. . . 6
	Careful installation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .	. . . 6. . . . . .
	Contamination and foreign particles . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .	. . . . 6. .
	Doing the pipe work . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .	. . . . 6. .
	Tubing layout of the condensing units with 1-cylinder compressors
	types TL, FR, NL, SC and SC-TWIN . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .	. . . 6. . . . . . .
	Tubing layout of the condensing units with hermetic Maneurop®
	reciprocating piston compressors, 1-2-4 cylinder . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .	. . . 8
	Leak check . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .	. . . .8. . . .
	Soldering . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .	. . .9. . . . .
	Protective gas . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .	. . .9. . . . . .
	Evacuating and filling . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .	. .10. . . . . . . .
	Exceeding the max.. allowable operational filling capacity and setting up outdoors . . . . . . . . . . .	. . 11. . . .
	General information: . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .	. .11. . . . . . .
	“Pump-down” . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .	. . 13. . . . . . . .
	Max.. allowable temperatures . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .	. 14. . . . . . .

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Notes

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Fitters’ Notes	Condensing units
General information	In the following you will find general information
on operating Danfoss	and practical tips for using Danfoss condensing
condensing units	units . Danfoss condensing units represent
	an integrated range of units with Danfoss
	reciprocating piston compressors. The versions
	and configurations of this series correspond
	to the requirements of the market. To give
	an overview of the program, the individual
	subsections are generally divided into the
	various hermetic compressors mounted on the
	condensing units.
	Condensing units with 1-cylinder compressors
	(types TL, FR, NL, GS, SC and SC-TWIN).
	Condensing units with hermetic 1 -2 and 4
	cylinder Maneurop® reciprocating piston
	compressors MTZ, NTZ and MPZ.

Equipment configuration	Danfoss condensing units are delivered with a
	compressor and condenser mounted on rails
	or a base plate. Terminal boxes are prewired. In
	addition, stop valves, solder adaptors, collectors,
	dual pressure switches and power cables with
	3-pin grounded plugs complete the delivery kit.

Please consult the corresponding Danfoss documentation or the current price list for details and ordering numbers. The Danfoss sales company responsible for your area will be glad to help you make your selection.

Power supply and electrical equipment

Condensing units with 1-cylinder compressors (types TL, FR, NL, GS, SC and SC-TWIN)

These condensing units are equipped with hermetic compressors and fans for 230 V 1-, 50 Hz power supply.

The compressors are equipped with an HST starting device consisting of a starting relay and a starting capacitor. The components can also be delivered as spare parts.

The starting capacitor is designed for short activation cycles (1.7% ED). In practice, this means that the compressors can perform up to 10 starts per hour with an activation duration of 6 seconds.

Condensing units with hermetic 1-2 and 4 cylinder Maneurop® reciprocating piston compressors MTZ and NTZ.

These condensing units are equipped with hermetic compressors and fan(s) for different voltage supplies:

• 400 V-3ph-50 Hz for compressor and for fan(s) .

•400 V-3ph-50Hz for compressor and

230 V-1ph-50Hz for fan(s) (the capacitor(s) of the fans are included inside the electrical box) .

•230 V-3ph-50Hz for compressor and

230 V-1ph-50Hz for fan(s) (the capacitor(s) of the fans are included inside the electrical box) .

•230 V-1ph-50Hz for compressor (the starting device (capcitors, relay) is included into the electrical box) and 230V-1ph-50Hz for fan(s)

The starting current of the Maneurop® threephase compressor can be reduced through the use of a soft starter. CI-tronicTM soft start, type MCI-C is recommended for use with this type of compressor. The starting current can be reduced up to 40% depending on the compressor model and the model of soft start used. The mechanical load that occurs at start-up is also reduced, which increases the lifespan of the internal components.

For details on the CI-tronicTM MCI-C soft start, please contact your local Danfoss dealer. The number of compressor starts is limited to 12 per hour in normal conditions. Pressure equalisation is recommended when MCI-C is used.

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Fitters’ Notes	Condensing units

Hermetic compressors	The hermetically sealed compressor types w,
	FR, NL, GS, SC and SC TWIN have a built-in
	winding protector.. When the protector is
	activated, a switch-off time of up to 45 minutes can
	occur as the result of heat storage in the motor..
	The single-phase Maneurop® compressors
	MTZ and NTZ are internally protected by a
	temperature/current sensing bimetallic protector,
	which senses the main and start winding currents
	and also the winding temperature..
	The three-phase Maneurop® reciprocating piston
	compressors MTZ and NTZ are equipped against
	over-current and over-temperature by internal
	motor protection.. The motor protection is located
	in the star point of the windings and opens all
	3 phases simultaneously via a bimetallic disk..
	After the compressor has switched off via the bi-
	metallic disc, reactivation can take up to 3 hours..

If the motor does not work, you can determine by means of resistance measurement whether the cause is a switched off winding protection switch or a possible broken winding..

Condensers and fans	Highly effective condensers allow a broader
	range of usage at higher ambient temperatures..
	One or two fan motors are used per condensing
	unit depending on the output value..
	In addition, the fans can be equipped, e..g.. with
	a Danfoss Saginomiya fan speed regulator, type
	RGE.. This allows good condensing pressure
	control and reduces the noise level.. The fans
	are provided with self-lubricating bearings,
	which ensures many years of maintenance-free
	operation..
Stop valves	Danfoss condensing units are provided with stop
	valves on the suction and liquid side..
	The stop valves of the condensing units with
	the 1-cylinder compressors (types TL, FR, NL,
	GS, SC and SC TWIN) are closed by turning the
	spindle clockwise to te soldered piece.. This opens
	the flow between the pressure gauge connection
	and the flare connection.. If you turn the spindle
	counter-clockwise to the rear stop, the pressure
	gauge connection is closed.. The flow between
	the soldered and the flare connection is free.. In
	the centre position, the flow through the three
	connections is free.. The accompanying soldered
	adapters help prevent flare connections and to
	make the system hermetic..
	The stop valves of the condensing units with
	Maneurop® reciprocating piston compressors
	MTZ and NTZ are directly fitted into the suction
	and discharge rotalock ports of the compressor
	and on the receiver.. The suction valve is provided
	with long, straight tube pieces in such a manner
	that soldered connections can be carried out
	without disassembling the Rotalock valve..

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Fitters’ Notes	Condensing units
Receiver	Liquid receiver is standard on Danfoss
	condensing units for use with expansion valves..
	The expansion valve is regulating the level in
	the receiver buffer (the deor increasing flow
	of the refrigerant).. The receivers from an internal
	volume of 3 l onwards are equipped with a
	Rotolock Valve..

Terminal box	The Danfoss condensing units are electrically
	pre-wired and equipped with a terminal box..
	Thus the power supply and additional electrical
	wiring can be easily fitted.. The terminal box of
	the condensing units with Maneurop®
	compressors is equipped with screw type
	connector blocks for both power and controls..

The electrical connections of each component (compressor, fan(s), PTC, pressure switch) are centralised into this box.. A wiring diagram is available in the cover of the electrical box.. These terminal boxes are protected to a degree of IP 54..

Safety pressure monitors	Danfoss condensing units can be ordered
	with safety pressure switches KP 17 (W, B…)..
	Condensing units that do not come equipped
	with pressure switches from the factory must
	be equipped with a pressure switch at least
	the high-pressure side in systems with
	thermostatic expansion valves as per EN 378..

LP A B

Start

Di .

Stop

HP A B

Stop

Di .

Start

The following settings are recommended:

Refrigerant	Low pressure side		High pressure side
	Cut in (bar)	Cut off (bar)	Cut in (bar)	Cut off (bar)
R407C	2	1	21	25
R404A/R507 MBP	1..2	0..5	24	28
R404A/R507 LBP	1	0..1	24	28
R134a	1..2	0..4	14	18

Setup	Danfoss condensing units must be set up in a		The ventilator motor is connected in such a way
	well ventilated location..		that the air is drawn in via the condenser in the
	You must ensure that there is sufficient fresh air		direction of the compressor..
	for the condenser at the intake end..		For optimal operation of the condensing unit,
	In addition, you must ensure that no cross-flow		the condenser must be cleaned regularly..
	occurs between the fresh air and the exhaust air..

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Fitters’ Notes	Condensing units
Protective weather-proof	Danfoss condensing units that are set up
housing	outside must be provided with a protective
	roof or with protective weather-resistant
	housing.. The scope of delivery includes
	optional, high-quality protective weather-
	proof housings..

Careful installation

Contamination and foreign particles

Doing the pipe work

Tubing layout of the condensing units with 1-cylinder compressors (types GS, TL, FR, NL, SC and SC-TWIN)

More and more commercial cooling and	hermetic compressors.. High demands are put
air-conditioning systems are installed with	on the quality of the installation work and the
condensing units that are equipped with	alignment of such a cooling system..

Contamination and foreign particles are among the most frequent causes that negatively impact the reliability and lifespan of cooling systems..

During the installation, the following types of contamination can enter the system:

Scaling during soldering (oxidations)Flux residue from soldering

Humidity and outside gasses

Shavings and copper residues from deburring the tubing

For this reason, Danfoss recommends the following precautions:

Use only clean and dry copper tubing and components that satisfy standard DIN 8964..

Danfoss offers a comprehensive and integral range of products for the necessary cooling automation.. Please contact your Danfoss dealer for additional information..

When laying the tubing, you should try to make the shortest and most compact pipe work possible.. Low-lying areas (oil traps), where oil might accumulate should be avoided..

1.. Condensing unit and evaporator are
located on the same level.
The suction line should be arranged slightly
downward from the compressor.. The max..
permissible distance between the condensing
unit and the cooling position (evaporator) is	Evaporator	Condenser
30 m..
		Compressor
Suction Line		Liquid Line

		Diameter copper pipe [mm]
TL	8		6
FR	10		6
NL	10		6
SC	10		8
GS	12/16		10
SC-TWIN	16		10

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Fitters’ Notes	Condensing units

Tubing layout of the condensing units with 1-cylinder compressors (types TL, FR, NL,SC, GS and SC-TWIN) (continued)

To ensure the oil return, the following crosssections are recommended for the intake and liquid lines:

2..The condensing unit is arranged above the evaporator.

The ideal height difference between the condensing unit and the evaporator position is a max.. of 5 m.. The tube length between the condensing unit and the evaporator should not exceed 30 m.. The suction lines must be laid out with double arcs in the form of oil traps above and below.. This is done using a U-shaped arc at the lower end and a P-shaped arc at the upper end of the vertical riser.. The max.. distance between the arcs is 1 to 1..5 m.. To ensure the oil return, the following pipe diameters are recommended for the suction and liquid lines:

	Suction Line		Liquid Line
		Diameter copper pipe [mm]
TL	8		6
FR	10		6
NL	10		6
SC 12/15	10		8
All other SCs	12		8
GS	16		10
SC TWIN	16		10

3..The condensing unit is arranged under the evaporator.

The ideal height difference between the condensing unit and the evaporator is a max.. of 5 m.. The tube length between the condensing unit and the evaporator should not exceed 30 m.. The suction lines must be laid out with double arcs in the form of oil traps above and below.. This is done using a U-shaped arc at the lower end and a P-shaped arc at the upper end of the vertical riser.. The max.. distance between the arcs is 1 to 1..5 m.. To ensure the oil return, the following pipe diameters are recommended for the suction and liquid lines:

Evaporator

Condenser

Compressor

	Suction Line		Liquid Line
		Diameter copper pipe [mm]
TL	8		6
FR	10		6
NL	10		6
SC	12		8
GS	16		10
SC TWIN	16		10

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