Control Circuit Transformers, Single Phase 50VA – 2.5kVA | CL Range

The CL Range 50VA–2.5kVA covers single-phase control circuit transformers designed for industrial control panels, machinery, automation systems and electrical control applications.

Manufactured in the UK by Boardman Transformers, this CL range offers 230V and 400V input tapping options and a selection of common secondary voltages, making it suitable for dependable control voltage transformation in industrial environments.

These control circuit transformers are designed and manufactured to comply with IEC / BS-EN 61558 and are built as Class 1 isolation transformers with an earth screen between primary and secondary windings.

This high quality product is manufactured using automated winding and welding machines; they offer good access to the four-hole fixing, touch-proof terminals and full varnish impregnation to protect against humidity.

Key Features

• – Single-phase CL control circuit transformer range
• – Ratings from 50VA to 2.5kVA
• – Designed for industrial control panels and machinery
• – 230V and 400V input tapping options
• – Secondary voltage options including 12V, 24V, 48V, 110V and 230V
• – Class 1 isolation transformer with earth screen between primary and secondary
• – Suitable for 50/60Hz applications
• – Designed and manufactured to comply with IEC / BS-EN 61558
• – UK manufactured by Boardman Transformers

Suitable Applications

The CL 50VA–2.5kVA range is suitable for industrial control applications where reliable single-phase voltage transformation is required.

• – Industrial control panels
• – Machinery control circuits
• – Automation systems
• – Panel builders
• – OEM electrical assemblies
• – Manufacturing equipment
• – Control circuit voltage transformation
• – Applications requiring 12V, 24V, 48V, 110V or 230V secondary outputs

Control Transformer	Class 1 Isolation Transformer with Earth Screen between Primary and Secondary
Standard	IEC / BS-EN 61558
Primary Voltages	0-220-230-240V Or 0-380-400-415V
Secondary Voltages	One of the following. 12V, 24V, 48V, 110V, 230V
Frequency	50/60Hz
Insulation Class	B
Insulation Resistance	> 5 Meg Ω
Dielectric Strength	Primary to Secondary >2.5kV Primary to Earth >2.5kV Secondary to Earth >2.5kV
Ambient Temperature	40℃

Transformer Circuit Protection

Transformers must be protected against short circuit and overload.

Primary Circuit

The primary side of the Transformer should be protected against short circuit thereby cutting the supply voltage in the event of a short circuit fault. The rating of the primary protection device has to take into account the high inrush current during energizing of the Transformer. The table below gives suggested protection values to avoid nuisance tripping on inrush.

Rating VA	Primary Volts	Amps	Fuse	Type C MCB	Type D MCB	Primary Volts	Amps	Fuse	Type C MCB	Type D MCB
50	230	0.21	1	1	1	415	0.12	500mA	1	1
75	230	0.27	1	1	1	415	0.15	500mA	1	1
100	230	0.43	1	2	1	415	0.24	1	1	1
150	230	0.65	2	2	1	415	0.36	1	1	1
200	230	0.86	2	6	2	415	0.48	1	2	1
250	230	1.09	3.15	6	2	415	0.60	2	2	1
300	230	1.2	3.15	6	3	415	0.72	2	2	2
500	230	2.17	4	10	3	415	1.20	3.15	6	4
750	230	3.26	6	10	4	415	1.80	3.15	6	4
1000	230	4.34	8	10	6	415	2.40	5	6	4
1500	230	6.52	10	16	10	415	3.61	6	10	6
2000	230	8.69	12	16	10	415	4.82	10	10	6
2500	230	10.86	16	25	16	415	6.02	10	16	10

Secondary Circuit

The secondary circuit should be protected against short circuit and overload.

The value of the protection should be the same or less than the rated output current.

Part No. VA	A	B	C	D	E	Weight kg	% Reg	Watts Loss	Inrush VA For 10% Volt drop	Inrush VA For 5% Volt drop
CL25	66	68	77	50	44	0.7	11	6	48	36
CL50	76	70	86	56	47	1.1	9.8	9	105	77
CL75	76	76	86	56	53	1.5	8.9	11	135	102
CL100	84	78	95	64	63	2.1	8.4	14	250	175
CL150	96	76	102	84	65	2.25	6.7	18	375	260
CL200	96	86	102	84	72	2.8	5.8	21	550	375
CL250	96	101	102	84	90	3.7	5.6	27	720	470
CL300	120	88	122	90	73	4.4	5.3	31	870	585
CL400	120	100	122	90	85	5.3	5.0	30	1200	790
CL500	120	120	122	90	106	6.5	4.1	31	1700	1100
CL750	150	145	140	122	90	8.0	5.2	60	2200	1475
CL1000	150	161	140	122	106	10.0	3.3	67	4000	2500
CL1500	150	188	140	122	134	14.0	3.2	88	6200	3850
CL2000	192	172	180	160	125	20.5	3.3	100	8060	5030
CL2500	192	192	180	160	153	24.0	2.6	120	12100	7300

Voltage Options and Part No.

Winding	Voltage	Code
Primary or Secondary	0-220-230-240V	U
	0-380-400-415V	N
	0-12V	J
	0-24V	B
	0-48V	E
	0-110V	F
	0-230V	U

For a 100VA Transformer, with input of 0-220-230-240V and an output of 110V, the Part Number would be CL100UF.

Power Rating Calculation

To choose the size of Transformer required for an application the total inrush VA must be calculated. This figure is then applied to the table above with the maximum allowable voltage drop taken into account. For example, for a calculated inrush of 2,100VA the appropriate transformer is as follows:

1. For 10% drop in output volts during inrush, choose 750 VA
2. For 5% drop in output volts during inrush, choose 1000 VA

Consideration must also be given to the continuous VA requirement.

Related Control Transformer Ranges

Need a larger single-phase transformer? View our CL 3kVA–40kVA range for higher-rated control and industrial transformer applications.

For a wider overview of our control transformer capability, visit our Control Transformers page