Tyler Refrigeration N7DNL, Installation & Service Manual

N7DNL, NHD

INSTALLATION PROCEDURES

Carpentry Procedures

Case Pull-Up Locations

All the N7DNL and NHD models have four 
pull-ups at each end of the case.  Pull-ups A,
B, C and D are located as shown and should
be installed and tightened starting with A and
finishing with D.  

NOTE

If extra pull-up bolts are needed, use the
bolts from the side shipping supports.  

See “General-UL/NSF I&S Manual” for 
line-up assembly instructions.

Electrical Procedures

Electrical Considerations

CAUTION

Make sure all electrical connections at 
components and terminal blocks are tight.
This will prevent burning of electrical 
terminals and/or premature component 
failure.

NOTE

Raceway covers will be shipped loose.  
See the “General-UL/NSF I&S Manual” for
raceway cover installation and removal
instructions.

Case Fan Circuit

This circuit is to be supplied by an uninter-
rupted, protected 120V circuit.  The case fan
circuit is not cycled, except when equipped
for gas defrost (NHD models only).  On gas
defrost cases the fans circuit is controlled by
a klixon.   

Fluorescent Lamp Circuit

The standard lighting for N7DNL and NHD
cases is 2 rows of T-8 canopy lights.  Optional
T-8 Nose Light is available on all models,
while T-8 shelf lighting is only available on 
the NHD models.    

Defrost Information

See “General-UL/NSF I&S Manual” for
operational descriptions for each type of
defrost control.

Defrost Control Charts

N7DNL Models

Defrost

Defrost

Defrosts Duration

Term.

Type

Per Day

(Min)

Temp.

Off Time

6

19

------

The N7DNL cases do not have any klixons.

NHD Models

Defrost

Defrost

Defrosts Duration

Term.

Type

Per Day

(Min)

Temp.

Off Time

4

24

------

Electric

4

24

41°F

Gas

4

15

55°F

Most klixons are located on the right end of
the evaporator coil.  

NOTE

The Gas Defrost Termination klixon is 
located at the by-pass check valve.

CAUTION

If electronic sensors are used in place of
the klixons, the sensors must be located in
the same location as the klixons for that
defrost type.  Any other locations will
effect the refrigeration efficiency of the
case.

June, 2007

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