GEA Searle NSQ Series, Installation And Maintenance Instructions Manual

1. HEALTH AND SAFETY 

This concerns the hazards, which may be encountered 
when installing and maintaining this equipment. It is 
therefore important that these instructions are followed. 

1

Before installation 

Ensure that: 
a) the voltage, working fluid and the maximum working 
pressure stated on the product nameplate is suitable for 
the working environment. 
b) the proposed method of mounting is adequate to 
support the total operational weight of the unit. 

During installation and maintenance 

Ensure that: 
a)  

the unit is installed and maintained by qualified 
personnel only. 

b)  the electrical supply is isolated and secured from 

accidental re-connection. 

c)  the working area is adequately ventilated.  
d)  the temperature of coils with vinyl coated fins does 

not exceed 150°C (e.g. during brazing) as toxic 
fumes would be produced. 

2. INSTALLATION 
General

Upon receipt, the units should be visually inspected and 
the supplier notified (within seven days) of any damage 
or shortages. Units are not portable and are only for 
permanent installation. Electrical screw terminals in 
control panels and motor mountings should be checked 
for security. 

Location 

To ensure optimum performance, the condensing unit 
should be situated to give uniform air distribution across 
the coil. Obstructions to airflow should be minimised.  
Coils should ideally be shaded from the sun. 
Consideration should also be given to servicing 
requirements - there should be at least 600mm 
clearance on the right hand side of the units, and access 
panels must be clear of obstruction. 

Floor/Roof Mounting 

When Floor Mounted a gap of 250mm 

must

be left 

between the rear of the unit and the nearest wall. 
Fixing holes are provided in the feet for securing the 
condensing unit to a plinth. If the condensing unit is roof 
mounted, it is recommended that isolation material be 
used between the feet of the unit and the roof itself. 

Guarding Cages

Floor mounted guard cages are available for individual 
units where additional protection to the installation may 
be required (contact your supplier for further details). 

Pipework 

Pipework to and from the unit should be selected to suit 
the application and not the connection size of the unit. It 
should be supported independently from the unit and in 
a way that prevents the transmission of vibration to the 
unit. A competent engineer should install refrigerant 

pipework to a high standard of refrigeration practice. 

Electrical

Electrical components are located in an enclosure, 
situated on the front RH side of the unit and behind a lift-
off service panel. Always ensure that the electrical 
supply to the unit is isolated before removing this panel. 
All electrical components are tested during the 
manufacturing process. 

The electrical supply to the unit must be taken from a 

correctly sized (and motor rated) main circuit breaker or 
fuse box, corresponding to the current shown on the 
unit's nameplate.  

Function of Controls 

(Please refer to the relevant wiring diagram in Sect. 10) 

a) Unit isolation

 - is situated behind a swivel plate 

cover on the main control box cover. 

b) HP/LP

 - The HP switch is to prevent overpressure 

within the system. It should only operate under fault 
conditions. The LP switch is to prevent too low a 
pressure. Pressure switches should be set to the 
required operating limits during commissioning. Do not 
adjust these switches outside of the acceptable 
operating limits, (see section 4). 

c) FSC

 - The fan speed controller is used to control the 

unit's head pressure under low ambient conditions. As 
the ambient temperature falls the fan speed is reduced 
to maintain head pressure.

Adjustment of FSC – Control Point  (2 Fan Units) 

The Fan Speed Controller is fitted on the rear port of the 
receiver outlet valve, and is factory set to maintain 39°C 
(17 barg R404A), if the desired Mid point differs from the 
factory setting it can be adjusted as follows: 

A n ti-C lo ckw ise
R e d u c e  S e tp o in t

C lo ckw ise
In cre a se  S e tp o in t

A d ju stm e n t
S c re w

Adjustment of FSC – Control Point  (4 Fan Units) 

The Fan Speed Controller is fitted on the control panel 
RH side, and uses a pressure sensor module mounted 
on the rear port of the receiver outlet valve, and is 
factory set to maintain 36.5°C (15.5 barg R404A). If the 
operating pressure falls below this setpoint the fans will 

Searle NSQ NSE NCQ
NCE NDQ SCQ

Installation and Maintenance Instructions

ENGLISH